Inference

Inference is the process that consists in computing new probabilistc information from a Bayesian network and some evidence. aGrUM/pyAgrum mainly focus on the computation of (joint) posterior for some variables of the Bayesian networks given soft or hard evidence that are the form of likelihoods on some variables. Inference is a hard task (NP-complete). aGrUM/pyAgrum implements exact inference but also approximated inference that can converge slowly and (even) not exactly but thant can in many cases be useful for applications.

Exact Inference

Lazy Propagation

Lazy Propagation is the main exact inference for classical Bayesian networks in aGrUM/pyAgrum.

class pyAgrum.LazyPropagation(*args)

Class used for Lazy Propagation

LazyPropagation(bn) -> LazyPropagation
Parameters:

  • bn (pyAgrum.BayesNet) – a Bayesian network

BN()
Returns:

A constant reference over the IBayesNet referenced by this class.

Return type:

pyAgrum.IBayesNet

Raises:

pyAgrum.UndefinedElement – If no Bayes net has been assigned to the inference.

H(X)

Deprecated I in LazyPropagation/ShaferShenoyMRFInference

I(X, Y)

Deprecated I in LazyPropagation/ShaferShenoyMRFInference

VI(X, Y)

Deprecated VI in LazyPropagation/ShaferShenoyMRFInference

addAllTargets()

Add all the nodes as targets.

Return type:

None

addEvidence(*args)

Adds a new evidence on a node (might be soft or hard).

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

  • val – (int) a node value

  • val – (str) the label of the node value

  • vals (list) – a list of values

Raises:
Return type:

None

addJointTarget(targets)

Add a list of nodes as a new joint target. As a collateral effect, every node is added as a marginal target.

Parameters:

  • list – a list of names of nodes

  • targets (object)

Raises:

pyAgrum.UndefinedElement – If some node(s) do not belong to the Bayesian network

Return type:

None

addTarget(*args)

Add a marginal target to the list of targets.

Parameters:

  • target (int) – a node Id

  • nodeName (str) – a node name

Raises:

pyAgrum.UndefinedElement – If target is not a NodeId in the Bayes net

Return type:

None

chgEvidence(*args)

Change the value of an already existing evidence on a node (might be soft or hard).

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

  • val (intstr) – a node value or the label of the node value

  • vals (List[float]) – a list of values

Raises:
Return type:

None

eraseAllEvidence()

Removes all the evidence entered into the network.

Return type:

None

eraseAllJointTargets()

Clear all previously defined joint targets.

Return type:

None

eraseAllMarginalTargets()

Clear all the previously defined marginal targets.

Return type:

None

eraseAllTargets()

Clear all previously defined targets (marginal and joint targets).

As a result, no posterior can be computed (since we can only compute the posteriors of the marginal or joint targets that have been added by the user).

Return type:

None

eraseEvidence(*args)

Remove the evidence, if any, corresponding to the node Id or name.

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

Return type:

None

eraseJointTarget(targets)

Remove, if existing, the joint target.

Parameters:

  • list – a list of names or Ids of nodes

  • targets (object)

Raises:

  • pyAgrum.IndexError – If one of the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

Return type:

None

eraseTarget(*args)

Remove, if existing, the marginal target.

Parameters:

  • target (int) – a node Id

  • nodeName (int) – a node name

Raises:

  • pyAgrum.IndexError – If one of the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

Return type:

None

evidenceImpact(target, evs)

Create a pyAgrum.Potential for P(target|evs) (for all instanciation of target and evs)

Parameters:

  • target (set) – a set of targets ids or names.

  • evs (set) – a set of nodes ids or names.

Warning

if some evs are d-separated, they are not included in the Potential.

Returns:

a Potential for P(targets|evs)

Return type:

pyAgrum.Potential

evidenceJointImpact(*args)

Create a pyAgrum.Potential for P(joint targets|evs) (for all instanciation of targets and evs)

Parameters:

  • targets (List[intstr]) – a list of node Ids or node names

  • evs (Set[intstr]) – a set of nodes ids or names.

Returns:

a Potential for P(target|evs)

Return type:

pyAgrum.Potential

Raises:

pyAgrum.Exception – If some evidene entered into the Bayes net are incompatible (their joint proba = 0)

evidenceProbability()
Returns:

the probability of evidence

Return type:

float

getNumberOfThreads()

returns the number of threads used by LazyPropagation during inferences.

Returns:

the number of threads used by LazyPropagation during inferences

Return type:

int

hardEvidenceNodes()
Returns:

the set of nodes with hard evidence

Return type:

set

hasEvidence(*args)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if some node(s) (or the one in parameters) have received evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

hasHardEvidence(nodeName)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if node has received a hard evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

hasSoftEvidence(*args)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if node has received a soft evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

isGumNumberOfThreadsOverriden()

Indicates whether LazyPropagation currently overrides aGrUM’s default number of threads (see method setNumberOfThreads).

Returns:

A Boolean indicating whether LazyPropagation currently overrides aGrUM’s default number of threads

Return type:

bool

isJointTarget(targets)
Parameters:

  • list – a list of nodes ids or names.

  • targets (object)

Returns:

True if target is a joint target.

Return type:

bool

Raises:

  • pyAgrum.IndexError – If the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

isTarget(*args)
Parameters:

  • variable (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if variable is a (marginal) target

Return type:

bool

Raises:

  • pyAgrum.IndexError – If the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

joinTree()
Returns:

the current join tree used

Return type:

pyAgrum.CliqueGraph

jointMutualInformation(targets)
Parameters:

targets (object)

Return type:

float

jointPosterior(targets)

Compute the joint posterior of a set of nodes.

Parameters:

list – the list of nodes whose posterior joint probability is wanted

Warning

The order of the variables given by the list here or when the jointTarget is declared can not be assumed to be used by the Potential.

Returns:

a const ref to the posterior joint probability of the set of nodes.

Return type:

pyAgrum.Potential

Raises:

pyAgrum.UndefinedElement – If an element of nodes is not in targets

Parameters:

targets (object)

jointTargets()
Returns:

the list of target sets

Return type:

list

junctionTree()
Returns:

the current junction tree

Return type:

pyAgrum.CliqueGraph

makeInference()

Perform the heavy computations needed to compute the targets’ posteriors

In a Junction tree propagation scheme, for instance, the heavy computations are those of the messages sent in the JT. This is precisely what makeInference should compute. Later, the computations of the posteriors can be done ‘lightly’ by multiplying and projecting those messages.

Return type:

None

mpe()

Find the Most Probable Explanation (MPE) given the evidence (if any) added into LazyPropagation

Returns:

An instantiation of all the variables of the Bayes net representing the Most Probable Explanation.

Return type:

pyAgrum.Instantiation

mpeLog2Posterior()

Find the Most Probable Explanation (MPE) given the evidence (if any) added into LazyPropagation as well as the log2 of its posterior probability

Returns:

A tuple with the instantiation of all the variables of the Bayes net representing the Most Probable Explanation and the log2 of its posterior probability

Return type:

Tuple[pyAgrum.Instantiation, float]

nbrEvidence()
Returns:

the number of evidence entered into the Bayesian network

Return type:

int

nbrHardEvidence()
Returns:

the number of hard evidence entered into the Bayesian network

Return type:

int

nbrJointTargets()
Returns:

the number of joint targets

Return type:

int

nbrSoftEvidence()
Returns:

the number of soft evidence entered into the Bayesian network

Return type:

int

nbrTargets()
Returns:

the number of marginal targets

Return type:

int

posterior(*args)

Computes and returns the posterior of a node.

Parameters:

  • var (int) – the node Id of the node for which we need a posterior probability

  • nodeName (str) – the node name of the node for which we need a posterior probability

Returns:

a const ref to the posterior probability of the node

Return type:

pyAgrum.Potential

Raises:

pyAgrum.UndefinedElement – If an element of nodes is not in targets

setEvidence(evidces)

Erase all the evidences and apply addEvidence(key,value) for every pairs in evidces.

Parameters:

evidces (Dict[str,Union[int,str,List[float]]] or List[pyAgrum.Potential]) – a dict of “name:evidence” where name is a string (the name of the variable) and evidence is an integer (an index) or a string (a label) or a list of float (a likelihood).

Raises:

pyAgrum.InvalidArgument – If one value is not a value for the node pyAgrum.InvalidArgument If the size of a value is different from the domain side of the node pyAgrum.FatalError If one value is a vector of 0s pyAgrum.UndefinedElement If one node does not belong to the Bayesian network

setMaxMemory(gigabytes)

sets an upper bound on the memory consumption admissible

Parameters:

gigabytes (float) – this upper bound in gigabytes.

Return type:

None

setNumberOfThreads(nb)

If the argument nb is different from 0, this number of threads will be used during inferences, hence overriding aGrUM’s default number of threads. If, on the contrary, nb is equal to 0, the parallelized inference engine will comply with aGrUM’s default number of threads.

Parameters:

nb (int) – the number of threads to be used by ShaferShenoyMRFInference

Return type:

None

setTargets(targets)

Remove all the targets and add the ones in parameter.

Parameters:

targets (set) – a set of targets

Raises:

pyAgrum.UndefinedElement – If one target is not in the Bayes net

softEvidenceNodes()
Returns:

the set of nodes with soft evidence

Return type:

set

targets()
Returns:

the list of marginal targets

Return type:

list

property thisown

The membership flag

updateEvidence(evidces)

Apply chgEvidence(key,value) for every pairs in evidces (or addEvidence).

Parameters:

evidces (Dict[str,Union[int,str,List[float]]] or List[pyAgrum.Potential]) – a dict of “name:evidence” where name is a string (the name of the variable) and evidence is an integer (an index) or a string (a label) or a list of float (a likelihood).

Raises:

Shafer-Shenoy Inference

class pyAgrum.ShaferShenoyInference(*args)

Class used for Shafer-Shenoy inferences.

ShaferShenoyInference(bn) -> ShaferShenoyInference
Parameters:

  • bn (pyAgrum.BayesNet) – a Bayesian network

BN()
Returns:

A constant reference over the IBayesNet referenced by this class.

Return type:

pyAgrum.IBayesNet

Raises:

pyAgrum.UndefinedElement – If no Bayes net has been assigned to the inference.

H(*args)
Parameters:

  • X (int) – a node Id

  • nodeName (str) – a node name

Returns:

the computed Shanon’s entropy of a node given the observation

Return type:

float

addAllTargets()

Add all the nodes as targets.

Return type:

None

addEvidence(*args)

Adds a new evidence on a node (might be soft or hard).

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

  • val – (int) a node value

  • val – (str) the label of the node value

  • vals (list) – a list of values

Raises:
Return type:

None

addJointTarget(targets)

Add a list of nodes as a new joint target. As a collateral effect, every node is added as a marginal target.

Parameters:

  • list – a list of names of nodes

  • targets (object)

Raises:

pyAgrum.UndefinedElement – If some node(s) do not belong to the Bayesian network

Return type:

None

addTarget(*args)

Add a marginal target to the list of targets.

Parameters:

  • target (int) – a node Id

  • nodeName (str) – a node name

Raises:

pyAgrum.UndefinedElement – If target is not a NodeId in the Bayes net

Return type:

None

chgEvidence(*args)

Change the value of an already existing evidence on a node (might be soft or hard).

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

  • val (intstr) – a node value or the label of the node value

  • vals (List[float]) – a list of values

Raises:
Return type:

None

eraseAllEvidence()

Removes all the evidence entered into the network.

Return type:

None

eraseAllJointTargets()

Clear all previously defined joint targets.

Return type:

None

eraseAllMarginalTargets()

Clear all the previously defined marginal targets.

Return type:

None

eraseAllTargets()

Clear all previously defined targets (marginal and joint targets).

As a result, no posterior can be computed (since we can only compute the posteriors of the marginal or joint targets that have been added by the user).

Return type:

None

eraseEvidence(*args)

Remove the evidence, if any, corresponding to the node Id or name.

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

Return type:

None

eraseJointTarget(targets)

Remove, if existing, the joint target.

Parameters:

  • list – a list of names or Ids of nodes

  • targets (object)

Raises:

  • pyAgrum.IndexError – If one of the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

Return type:

None

eraseTarget(*args)

Remove, if existing, the marginal target.

Parameters:

  • target (int) – a node Id

  • nodeName (int) – a node name

Raises:

  • pyAgrum.IndexError – If one of the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

Return type:

None

evidenceImpact(target, evs)

Create a pyAgrum.Potential for P(target|evs) (for all instanciation of target and evs)

Parameters:

  • target (set) – a set of targets ids or names.

  • evs (set) – a set of nodes ids or names.

Warning

if some evs are d-separated, they are not included in the Potential.

Returns:

a Potential for P(targets|evs)

Return type:

pyAgrum.Potential

evidenceJointImpact(*args)

Create a pyAgrum.Potential for P(joint targets|evs) (for all instanciation of targets and evs)

Parameters:

  • targets (List[intstr]) – a list of node Ids or node names

  • evs (Set[intstr]) – a set of nodes ids or names.

Returns:

a Potential for P(target|evs)

Return type:

pyAgrum.Potential

Raises:

pyAgrum.Exception – If some evidene entered into the Bayes net are incompatible (their joint proba = 0)

evidenceProbability()
Returns:

the probability of evidence

Return type:

float

getNumberOfThreads()

returns the number of threads used by LazyPropagation during inferences.

Returns:

the number of threads used by LazyPropagation during inferences

Return type:

int

hardEvidenceNodes()
Returns:

the set of nodes with hard evidence

Return type:

set

hasEvidence(*args)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if some node(s) (or the one in parameters) have received evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

hasHardEvidence(nodeName)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if node has received a hard evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

hasSoftEvidence(*args)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if node has received a soft evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

isGumNumberOfThreadsOverriden()

Indicates whether LazyPropagation currently overrides aGrUM’s default number of threads (see method setNumberOfThreads).

Returns:

A Boolean indicating whether LazyPropagation currently overrides aGrUM’s default number of threads

Return type:

bool

isJointTarget(targets)
Parameters:

  • list – a list of nodes ids or names.

  • targets (object)

Returns:

True if target is a joint target.

Return type:

bool

Raises:

  • pyAgrum.IndexError – If the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

isTarget(*args)
Parameters:

  • variable (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if variable is a (marginal) target

Return type:

bool

Raises:

  • pyAgrum.IndexError – If the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

joinTree()
Returns:

the current join tree used

Return type:

pyAgrum.CliqueGraph

jointMutualInformation(targets)
Parameters:

targets (object)

Return type:

float

jointPosterior(targets)

Compute the joint posterior of a set of nodes.

Parameters:

list – the list of nodes whose posterior joint probability is wanted

Warning

The order of the variables given by the list here or when the jointTarget is declared can not be assumed to be used by the Potential.

Returns:

a const ref to the posterior joint probability of the set of nodes.

Return type:

pyAgrum.Potential

Raises:

pyAgrum.UndefinedElement – If an element of nodes is not in targets

Parameters:

targets (object)

jointTargets()
Returns:

the list of target sets

Return type:

list

junctionTree()
Returns:

the current junction tree

Return type:

pyAgrum.CliqueGraph

makeInference()

Perform the heavy computations needed to compute the targets’ posteriors

In a Junction tree propagation scheme, for instance, the heavy computations are those of the messages sent in the JT. This is precisely what makeInference should compute. Later, the computations of the posteriors can be done ‘lightly’ by multiplying and projecting those messages.

Return type:

None

nbrEvidence()
Returns:

the number of evidence entered into the Bayesian network

Return type:

int

nbrHardEvidence()
Returns:

the number of hard evidence entered into the Bayesian network

Return type:

int

nbrJointTargets()
Returns:

the number of joint targets

Return type:

int

nbrSoftEvidence()
Returns:

the number of soft evidence entered into the Bayesian network

Return type:

int

nbrTargets()
Returns:

the number of marginal targets

Return type:

int

posterior(*args)

Computes and returns the posterior of a node.

Parameters:

  • var (int) – the node Id of the node for which we need a posterior probability

  • nodeName (str) – the node name of the node for which we need a posterior probability

Returns:

a const ref to the posterior probability of the node

Return type:

pyAgrum.Potential

Raises:

pyAgrum.UndefinedElement – If an element of nodes is not in targets

setEvidence(evidces)

Erase all the evidences and apply addEvidence(key,value) for every pairs in evidces.

Parameters:

evidces (Dict[str,Union[int,str,List[float]]] or List[pyAgrum.Potential]) – a dict of “name:evidence” where name is a string (the name of the variable) and evidence is an integer (an index) or a string (a label) or a list of float (a likelihood).

Raises:

pyAgrum.InvalidArgument – If one value is not a value for the node pyAgrum.InvalidArgument If the size of a value is different from the domain side of the node pyAgrum.FatalError If one value is a vector of 0s pyAgrum.UndefinedElement If one node does not belong to the Bayesian network

setMaxMemory(gigabytes)

sets an upper bound on the memory consumption admissible

Parameters:

gigabytes (float) – this upper bound in gigabytes.

Return type:

None

setNumberOfThreads(nb)

If the argument nb is different from 0, this number of threads will be used during inferences, hence overriding aGrUM’s default number of threads. If, on the contrary, nb is equal to 0, the parallelized inference engine will comply with aGrUM’s default number of threads.

Parameters:

nb (int) – the number of threads to be used by ShaferShenoyMRFInference

Return type:

None

setTargets(targets)

Remove all the targets and add the ones in parameter.

Parameters:

targets (set) – a set of targets

Raises:

pyAgrum.UndefinedElement – If one target is not in the Bayes net

softEvidenceNodes()
Returns:

the set of nodes with soft evidence

Return type:

set

targets()
Returns:

the list of marginal targets

Return type:

list

property thisown

The membership flag

updateEvidence(evidces)

Apply chgEvidence(key,value) for every pairs in evidces (or addEvidence).

Parameters:

evidces (Dict[str,Union[int,str,List[float]]] or List[pyAgrum.Potential]) – a dict of “name:evidence” where name is a string (the name of the variable) and evidence is an integer (an index) or a string (a label) or a list of float (a likelihood).

Raises:

Variable Elimination

class pyAgrum.VariableElimination(*args)

Class used for Variable Elimination inference algorithm.

Warning

Even if this inference has the same API than the other (exact) inferences, its mode of operation is different and is specifically dedicated to the calculation of a single posterior. Any other use (for instance for multiple targets) is possibly inefficient.

VariableElimination(bn) -> VariableElimination
Parameters:

  • bn (pyAgrum.BayesNet) – a Bayesian network

BN()
Returns:

A constant reference over the IBayesNet referenced by this class.

Return type:

pyAgrum.IBayesNet

Raises:

pyAgrum.UndefinedElement – If no Bayes net has been assigned to the inference.

H(*args)
Parameters:

  • X (int) – a node Id

  • nodeName (str) – a node name

Returns:

the computed Shanon’s entropy of a node given the observation

Return type:

float

addAllTargets()

Add all the nodes as targets.

Return type:

None

addEvidence(*args)

Adds a new evidence on a node (might be soft or hard).

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

  • val – (int) a node value

  • val – (str) the label of the node value

  • vals (list) – a list of values

Raises:
Return type:

None

addJointTarget(targets)

Add a list of nodes as a new joint target. As a collateral effect, every node is added as a marginal target.

Parameters:

  • list – a list of names of nodes

  • targets (object)

Raises:

pyAgrum.UndefinedElement – If some node(s) do not belong to the Bayesian network

Return type:

None

addTarget(*args)

Add a marginal target to the list of targets.

Parameters:

  • target (int) – a node Id

  • nodeName (str) – a node name

Raises:

pyAgrum.UndefinedElement – If target is not a NodeId in the Bayes net

Return type:

None

chgEvidence(*args)

Change the value of an already existing evidence on a node (might be soft or hard).

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

  • val (intstr) – a node value or the label of the node value

  • vals (List[float]) – a list of values

Raises:
Return type:

None

eraseAllEvidence()

Removes all the evidence entered into the network.

Return type:

None

eraseAllTargets()

Clear all previously defined targets (marginal and joint targets).

As a result, no posterior can be computed (since we can only compute the posteriors of the marginal or joint targets that have been added by the user).

Return type:

None

eraseEvidence(*args)

Remove the evidence, if any, corresponding to the node Id or name.

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

Return type:

None

eraseJointTarget(targets)

Remove, if existing, the joint target.

Parameters:

  • list – a list of names or Ids of nodes

  • targets (object)

Raises:

  • pyAgrum.IndexError – If one of the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

Return type:

None

eraseTarget(*args)

Remove, if existing, the marginal target.

Parameters:

  • target (int) – a node Id

  • nodeName (int) – a node name

Raises:

  • pyAgrum.IndexError – If one of the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

Return type:

None

evidenceImpact(target, evs)

Create a pyAgrum.Potential for P(target|evs) (for all instanciation of target and evs)

Parameters:

  • target (set) – a set of targets ids or names.

  • evs (set) – a set of nodes ids or names.

Warning

if some evs are d-separated, they are not included in the Potential.

Returns:

a Potential for P(targets|evs)

Return type:

pyAgrum.Potential

evidenceJointImpact(targets, evs)

Create a pyAgrum.Potential for P(joint targets|evs) (for all instanciation of targets and evs)

Parameters:

  • targets (List[intstr]) – a list of node Ids or node names

  • evs (Set[intstr]) – a set of nodes ids or names.

Returns:

a Potential for P(target|evs)

Return type:

pyAgrum.Potential

Raises:

pyAgrum.Exception – If some evidene entered into the Bayes net are incompatible (their joint proba = 0)

getNumberOfThreads()

returns the number of threads used by LazyPropagation during inferences.

Returns:

the number of threads used by LazyPropagation during inferences

Return type:

int

hardEvidenceNodes()
Returns:

the set of nodes with hard evidence

Return type:

set

hasEvidence(*args)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if some node(s) (or the one in parameters) have received evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

hasHardEvidence(nodeName)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if node has received a hard evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

hasSoftEvidence(*args)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if node has received a soft evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

isGumNumberOfThreadsOverriden()

Indicates whether LazyPropagation currently overrides aGrUM’s default number of threads (see method setNumberOfThreads).

Returns:

A Boolean indicating whether LazyPropagation currently overrides aGrUM’s default number of threads

Return type:

bool

isJointTarget(targets)
Parameters:

  • list – a list of nodes ids or names.

  • targets (object)

Returns:

True if target is a joint target.

Return type:

bool

Raises:

  • pyAgrum.IndexError – If the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

isTarget(*args)
Parameters:

  • variable (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if variable is a (marginal) target

Return type:

bool

Raises:

  • pyAgrum.IndexError – If the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

jointMutualInformation(targets)
Parameters:

targets (object)

Return type:

float

jointPosterior(targets)

Compute the joint posterior of a set of nodes.

Parameters:

list – the list of nodes whose posterior joint probability is wanted

Warning

The order of the variables given by the list here or when the jointTarget is declared can not be assumed to be used by the Potential.

Returns:

a const ref to the posterior joint probability of the set of nodes.

Return type:

pyAgrum.Potential

Raises:

pyAgrum.UndefinedElement – If an element of nodes is not in targets

Parameters:

targets (object)

jointTargets()
Returns:

the list of target sets

Return type:

list

junctionTree(id)
Returns:

the current junction tree

Return type:

pyAgrum.CliqueGraph

makeInference()

Perform the heavy computations needed to compute the targets’ posteriors

In a Junction tree propagation scheme, for instance, the heavy computations are those of the messages sent in the JT. This is precisely what makeInference should compute. Later, the computations of the posteriors can be done ‘lightly’ by multiplying and projecting those messages.

Return type:

None

nbrEvidence()
Returns:

the number of evidence entered into the Bayesian network

Return type:

int

nbrHardEvidence()
Returns:

the number of hard evidence entered into the Bayesian network

Return type:

int

nbrSoftEvidence()
Returns:

the number of soft evidence entered into the Bayesian network

Return type:

int

nbrTargets()
Returns:

the number of marginal targets

Return type:

int

posterior(*args)

Computes and returns the posterior of a node.

Parameters:

  • var (int) – the node Id of the node for which we need a posterior probability

  • nodeName (str) – the node name of the node for which we need a posterior probability

Returns:

a const ref to the posterior probability of the node

Return type:

pyAgrum.Potential

Raises:

pyAgrum.UndefinedElement – If an element of nodes is not in targets

setEvidence(evidces)

Erase all the evidences and apply addEvidence(key,value) for every pairs in evidces.

Parameters:

evidces (Dict[str,Union[int,str,List[float]]] or List[pyAgrum.Potential]) – a dict of “name:evidence” where name is a string (the name of the variable) and evidence is an integer (an index) or a string (a label) or a list of float (a likelihood).

Raises:

pyAgrum.InvalidArgument – If one value is not a value for the node pyAgrum.InvalidArgument If the size of a value is different from the domain side of the node pyAgrum.FatalError If one value is a vector of 0s pyAgrum.UndefinedElement If one node does not belong to the Bayesian network

setMaxMemory(gigabytes)

sets an upper bound on the memory consumption admissible

Parameters:

gigabytes (float) – this upper bound in gigabytes.

Return type:

None

setNumberOfThreads(nb)

If the argument nb is different from 0, this number of threads will be used during inferences, hence overriding aGrUM’s default number of threads. If, on the contrary, nb is equal to 0, the parallelized inference engine will comply with aGrUM’s default number of threads.

Parameters:

nb (int) – the number of threads to be used by ShaferShenoyMRFInference

Return type:

None

setTargets(targets)

Remove all the targets and add the ones in parameter.

Parameters:

targets (set) – a set of targets

Raises:

pyAgrum.UndefinedElement – If one target is not in the Bayes net

softEvidenceNodes()
Returns:

the set of nodes with soft evidence

Return type:

set

targets()
Returns:

the list of marginal targets

Return type:

list

property thisown

The membership flag

updateEvidence(evidces)

Apply chgEvidence(key,value) for every pairs in evidces (or addEvidence).

Parameters:

evidces (Dict[str,Union[int,str,List[float]]] or List[pyAgrum.Potential]) – a dict of “name:evidence” where name is a string (the name of the variable) and evidence is an integer (an index) or a string (a label) or a list of float (a likelihood).

Raises:

Approximated Inference

Loopy Belief Propagation

class pyAgrum.LoopyBeliefPropagation(bn)

Class used for inferences using loopy belief propagation algorithm.

LoopyBeliefPropagation(bn) -> LoopyBeliefPropagation
Parameters:

  • bn (pyAgrum.BayesNet) – a Bayesian network

Parameters:

bn (IBayesNet)

BN()
Returns:

A constant reference over the IBayesNet referenced by this class.

Return type:

pyAgrum.IBayesNet

Raises:

pyAgrum.UndefinedElement – If no Bayes net has been assigned to the inference.

H(*args)
Parameters:

  • X (int) – a node Id

  • nodeName (str) – a node name

Returns:

the computed Shanon’s entropy of a node given the observation

Return type:

float

addAllTargets()

Add all the nodes as targets.

Return type:

None

addEvidence(*args)

Adds a new evidence on a node (might be soft or hard).

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

  • val – (int) a node value

  • val – (str) the label of the node value

  • vals (list) – a list of values

Raises:
Return type:

None

addTarget(*args)

Add a marginal target to the list of targets.

Parameters:

  • target (int) – a node Id

  • nodeName (str) – a node name

Raises:

pyAgrum.UndefinedElement – If target is not a NodeId in the Bayes net

Return type:

None

chgEvidence(*args)

Change the value of an already existing evidence on a node (might be soft or hard).

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

  • val (intstr) – a node value or the label of the node value

  • vals (List[float]) – a list of values

Raises:
Return type:

None

currentTime()
Returns:

get the current running time in second (float)

Return type:

float

epsilon()
Returns:

the value of epsilon

Return type:

float

eraseAllEvidence()

Removes all the evidence entered into the network.

Return type:

None

eraseAllTargets()

Clear all previously defined targets (marginal and joint targets).

As a result, no posterior can be computed (since we can only compute the posteriors of the marginal or joint targets that have been added by the user).

Return type:

None

eraseEvidence(*args)

Remove the evidence, if any, corresponding to the node Id or name.

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

Return type:

None

eraseTarget(*args)

Remove, if existing, the marginal target.

Parameters:

  • target (int) – a node Id

  • nodeName (int) – a node name

Raises:

  • pyAgrum.IndexError – If one of the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

Return type:

None

evidenceImpact(target, evs)

Create a pyAgrum.Potential for P(target|evs) (for all instanciation of target and evs)

Parameters:

  • target (set) – a set of targets ids or names.

  • evs (set) – a set of nodes ids or names.

Warning

if some evs are d-separated, they are not included in the Potential.

Returns:

a Potential for P(targets|evs)

Return type:

pyAgrum.Potential

hardEvidenceNodes()
Returns:

the set of nodes with hard evidence

Return type:

set

hasEvidence(*args)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if some node(s) (or the one in parameters) have received evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

hasHardEvidence(nodeName)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if node has received a hard evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

hasSoftEvidence(*args)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if node has received a soft evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

history()
Returns:

the scheme history

Return type:

tuple

Raises:

pyAgrum.OperationNotAllowed – If the scheme did not performed or if verbosity is set to false

isTarget(*args)
Parameters:

  • variable (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if variable is a (marginal) target

Return type:

bool

Raises:

  • pyAgrum.IndexError – If the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

makeInference()

Perform the heavy computations needed to compute the targets’ posteriors

In a Junction tree propagation scheme, for instance, the heavy computations are those of the messages sent in the JT. This is precisely what makeInference should compute. Later, the computations of the posteriors can be done ‘lightly’ by multiplying and projecting those messages.

Return type:

None

maxIter()
Returns:

the criterion on number of iterations

Return type:

int

maxTime()
Returns:

the timeout(in seconds)

Return type:

float

messageApproximationScheme()
Returns:

the approximation scheme message

Return type:

str

minEpsilonRate()
Returns:

the value of the minimal epsilon rate

Return type:

float

nbrEvidence()
Returns:

the number of evidence entered into the Bayesian network

Return type:

int

nbrHardEvidence()
Returns:

the number of hard evidence entered into the Bayesian network

Return type:

int

nbrIterations()
Returns:

the number of iterations

Return type:

int

nbrSoftEvidence()
Returns:

the number of soft evidence entered into the Bayesian network

Return type:

int

nbrTargets()
Returns:

the number of marginal targets

Return type:

int

periodSize()
Returns:

the number of samples between 2 stopping

Return type:

int

Raises:

pyAgrum.OutOfBounds – If p<1

posterior(*args)

Computes and returns the posterior of a node.

Parameters:

  • var (int) – the node Id of the node for which we need a posterior probability

  • nodeName (str) – the node name of the node for which we need a posterior probability

Returns:

a const ref to the posterior probability of the node

Return type:

pyAgrum.Potential

Raises:

pyAgrum.UndefinedElement – If an element of nodes is not in targets

setEpsilon(eps)
Parameters:

eps (float) – the epsilon we want to use

Raises:

pyAgrum.OutOfBounds – If eps<0

Return type:

None

setEvidence(evidces)

Erase all the evidences and apply addEvidence(key,value) for every pairs in evidces.

Parameters:

evidces (Dict[str,Union[int,str,List[float]]] or List[pyAgrum.Potential]) – a dict of “name:evidence” where name is a string (the name of the variable) and evidence is an integer (an index) or a string (a label) or a list of float (a likelihood).

Raises:

pyAgrum.InvalidArgument – If one value is not a value for the node pyAgrum.InvalidArgument If the size of a value is different from the domain side of the node pyAgrum.FatalError If one value is a vector of 0s pyAgrum.UndefinedElement If one node does not belong to the Bayesian network

setMaxIter(max)
Parameters:

max (int) – the maximum number of iteration

Raises:

pyAgrum.OutOfBounds – If max <= 1

Return type:

None

setMaxTime(timeout)
Parameters:

  • tiemout (float) – stopping criterion on timeout (in seconds)

  • timeout (float)

Raises:

pyAgrum.OutOfBounds – If timeout<=0.0

Return type:

None

setMinEpsilonRate(rate)
Parameters:

rate (float) – the minimal epsilon rate

Return type:

None

setPeriodSize(p)
Parameters:

p (int) – number of samples between 2 stopping

Raises:

pyAgrum.OutOfBounds – If p<1

Return type:

None

setTargets(targets)

Remove all the targets and add the ones in parameter.

Parameters:

targets (set) – a set of targets

Raises:

pyAgrum.UndefinedElement – If one target is not in the Bayes net

setVerbosity(v)
Parameters:

v (bool) – verbosity

Return type:

None

softEvidenceNodes()
Returns:

the set of nodes with soft evidence

Return type:

set

targets()
Returns:

the list of marginal targets

Return type:

list

property thisown

The membership flag

updateEvidence(evidces)

Apply chgEvidence(key,value) for every pairs in evidces (or addEvidence).

Parameters:

evidces (Dict[str,Union[int,str,List[float]]] or List[pyAgrum.Potential]) – a dict of “name:evidence” where name is a string (the name of the variable) and evidence is an integer (an index) or a string (a label) or a list of float (a likelihood).

Raises:
verbosity()
Returns:

True if the verbosity is enabled

Return type:

bool

Sampling

Gibbs Sampling for BN

class pyAgrum.GibbsSampling(bn)

Class for making Gibbs sampling inference in Bayesian networks.

GibbsSampling(bn) -> GibbsSampling
Parameters:

  • bn (pyAgrum.BayesNet) – a Bayesian network

Parameters:

bn (IBayesNet)

BN()
Returns:

A constant reference over the IBayesNet referenced by this class.

Return type:

pyAgrum.IBayesNet

Raises:

pyAgrum.UndefinedElement – If no Bayes net has been assigned to the inference.

H(*args)
Parameters:

  • X (int) – a node Id

  • nodeName (str) – a node name

Returns:

the computed Shanon’s entropy of a node given the observation

Return type:

float

addAllTargets()

Add all the nodes as targets.

Return type:

None

addEvidence(*args)

Adds a new evidence on a node (might be soft or hard).

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

  • val – (int) a node value

  • val – (str) the label of the node value

  • vals (list) – a list of values

Raises:
Return type:

None

addTarget(*args)

Add a marginal target to the list of targets.

Parameters:

  • target (int) – a node Id

  • nodeName (str) – a node name

Raises:

pyAgrum.UndefinedElement – If target is not a NodeId in the Bayes net

Return type:

None

burnIn()
Returns:

size of burn in on number of iteration

Return type:

int

chgEvidence(*args)

Change the value of an already existing evidence on a node (might be soft or hard).

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

  • val (intstr) – a node value or the label of the node value

  • vals (List[float]) – a list of values

Raises:
Return type:

None

currentPosterior(*args)

Computes and returns the current posterior of a node.

Parameters:

  • var (int) – the node Id of the node for which we need a posterior probability

  • nodeName (str) – the node name of the node for which we need a posterior probability

Returns:

a const ref to the current posterior probability of the node

Return type:

pyAgrum.Potential

Raises:

UndefinedElement – If an element of nodes is not in targets

currentTime()
Returns:

get the current running time in second (float)

Return type:

float

epsilon()
Returns:

the value of epsilon

Return type:

float

eraseAllEvidence()

Removes all the evidence entered into the network.

Return type:

None

eraseAllTargets()

Clear all previously defined targets (marginal and joint targets).

As a result, no posterior can be computed (since we can only compute the posteriors of the marginal or joint targets that have been added by the user).

Return type:

None

eraseEvidence(*args)

Remove the evidence, if any, corresponding to the node Id or name.

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

Return type:

None

eraseTarget(*args)

Remove, if existing, the marginal target.

Parameters:

  • target (int) – a node Id

  • nodeName (int) – a node name

Raises:

  • pyAgrum.IndexError – If one of the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

Return type:

None

evidenceImpact(target, evs)

Create a pyAgrum.Potential for P(target|evs) (for all instanciation of target and evs)

Parameters:

  • target (set) – a set of targets ids or names.

  • evs (set) – a set of nodes ids or names.

Warning

if some evs are d-separated, they are not included in the Potential.

Returns:

a Potential for P(targets|evs)

Return type:

pyAgrum.Potential

hardEvidenceNodes()
Returns:

the set of nodes with hard evidence

Return type:

set

hasEvidence(*args)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if some node(s) (or the one in parameters) have received evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

hasHardEvidence(nodeName)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if node has received a hard evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

hasSoftEvidence(*args)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if node has received a soft evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

history()
Returns:

the scheme history

Return type:

tuple

Raises:

pyAgrum.OperationNotAllowed – If the scheme did not performed or if verbosity is set to false

isDrawnAtRandom()
Returns:

True if variables are drawn at random

Return type:

bool

isTarget(*args)
Parameters:

  • variable (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if variable is a (marginal) target

Return type:

bool

Raises:

  • pyAgrum.IndexError – If the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

makeInference()

Perform the heavy computations needed to compute the targets’ posteriors

In a Junction tree propagation scheme, for instance, the heavy computations are those of the messages sent in the JT. This is precisely what makeInference should compute. Later, the computations of the posteriors can be done ‘lightly’ by multiplying and projecting those messages.

Return type:

None

maxIter()
Returns:

the criterion on number of iterations

Return type:

int

maxTime()
Returns:

the timeout(in seconds)

Return type:

float

messageApproximationScheme()
Returns:

the approximation scheme message

Return type:

str

minEpsilonRate()
Returns:

the value of the minimal epsilon rate

Return type:

float

nbrDrawnVar()
Returns:

the number of variable drawn at each iteration

Return type:

int

nbrEvidence()
Returns:

the number of evidence entered into the Bayesian network

Return type:

int

nbrHardEvidence()
Returns:

the number of hard evidence entered into the Bayesian network

Return type:

int

nbrIterations()
Returns:

the number of iterations

Return type:

int

nbrSoftEvidence()
Returns:

the number of soft evidence entered into the Bayesian network

Return type:

int

nbrTargets()
Returns:

the number of marginal targets

Return type:

int

periodSize()
Returns:

the number of samples between 2 stopping

Return type:

int

Raises:

pyAgrum.OutOfBounds – If p<1

posterior(*args)

Computes and returns the posterior of a node.

Parameters:

  • var (int) – the node Id of the node for which we need a posterior probability

  • nodeName (str) – the node name of the node for which we need a posterior probability

Returns:

a const ref to the posterior probability of the node

Return type:

pyAgrum.Potential

Raises:

pyAgrum.UndefinedElement – If an element of nodes is not in targets

setBurnIn(b)
Parameters:

b (int) – size of burn in on number of iteration

Return type:

None

setDrawnAtRandom(_atRandom)
Parameters:

_atRandom (bool) – indicates if variables should be drawn at random

Return type:

None

setEpsilon(eps)
Parameters:

eps (float) – the epsilon we want to use

Raises:

pyAgrum.OutOfBounds – If eps<0

Return type:

None

setEvidence(evidces)

Erase all the evidences and apply addEvidence(key,value) for every pairs in evidces.

Parameters:

evidces (Dict[str,Union[int,str,List[float]]] or List[pyAgrum.Potential]) – a dict of “name:evidence” where name is a string (the name of the variable) and evidence is an integer (an index) or a string (a label) or a list of float (a likelihood).

Raises:

pyAgrum.InvalidArgument – If one value is not a value for the node pyAgrum.InvalidArgument If the size of a value is different from the domain side of the node pyAgrum.FatalError If one value is a vector of 0s pyAgrum.UndefinedElement If one node does not belong to the Bayesian network

setMaxIter(max)
Parameters:

max (int) – the maximum number of iteration

Raises:

pyAgrum.OutOfBounds – If max <= 1

Return type:

None

setMaxTime(timeout)
Parameters:

  • tiemout (float) – stopping criterion on timeout (in seconds)

  • timeout (float)

Raises:

pyAgrum.OutOfBounds – If timeout<=0.0

Return type:

None

setMinEpsilonRate(rate)
Parameters:

rate (float) – the minimal epsilon rate

Return type:

None

setNbrDrawnVar(_nbr)
Parameters:

_nbr (int) – the number of variables to be drawn at each iteration

Return type:

None

setPeriodSize(p)
Parameters:

p (int) – number of samples between 2 stopping

Raises:

pyAgrum.OutOfBounds – If p<1

Return type:

None

setTargets(targets)

Remove all the targets and add the ones in parameter.

Parameters:

targets (set) – a set of targets

Raises:

pyAgrum.UndefinedElement – If one target is not in the Bayes net

setVerbosity(v)
Parameters:

v (bool) – verbosity

Return type:

None

softEvidenceNodes()
Returns:

the set of nodes with soft evidence

Return type:

set

targets()
Returns:

the list of marginal targets

Return type:

list

property thisown

The membership flag

updateEvidence(evidces)

Apply chgEvidence(key,value) for every pairs in evidces (or addEvidence).

Parameters:

evidces (Dict[str,Union[int,str,List[float]]] or List[pyAgrum.Potential]) – a dict of “name:evidence” where name is a string (the name of the variable) and evidence is an integer (an index) or a string (a label) or a list of float (a likelihood).

Raises:
verbosity()
Returns:

True if the verbosity is enabled

Return type:

bool

Simple Monte Carlo Sampling for BN

class pyAgrum.MonteCarloSampling(bn)

Class used for Monte Carlo sampling inference algorithm.

MonteCarloSampling(bn) -> MonteCarloSampling
Parameters:

  • bn (pyAgrum.BayesNet) – a Bayesian network

Parameters:

bn (IBayesNet)

BN()
Returns:

A constant reference over the IBayesNet referenced by this class.

Return type:

pyAgrum.IBayesNet

Raises:

pyAgrum.UndefinedElement – If no Bayes net has been assigned to the inference.

H(*args)
Parameters:

  • X (int) – a node Id

  • nodeName (str) – a node name

Returns:

the computed Shanon’s entropy of a node given the observation

Return type:

float

addAllTargets()

Add all the nodes as targets.

Return type:

None

addEvidence(*args)

Adds a new evidence on a node (might be soft or hard).

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

  • val – (int) a node value

  • val – (str) the label of the node value

  • vals (list) – a list of values

Raises:
Return type:

None

addTarget(*args)

Add a marginal target to the list of targets.

Parameters:

  • target (int) – a node Id

  • nodeName (str) – a node name

Raises:

pyAgrum.UndefinedElement – If target is not a NodeId in the Bayes net

Return type:

None

chgEvidence(*args)

Change the value of an already existing evidence on a node (might be soft or hard).

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

  • val (intstr) – a node value or the label of the node value

  • vals (List[float]) – a list of values

Raises:
Return type:

None

currentPosterior(*args)

Computes and returns the current posterior of a node.

Parameters:

  • var (int) – the node Id of the node for which we need a posterior probability

  • nodeName (str) – the node name of the node for which we need a posterior probability

Returns:

a const ref to the current posterior probability of the node

Return type:

pyAgrum.Potential

Raises:

UndefinedElement – If an element of nodes is not in targets

currentTime()
Returns:

get the current running time in second (float)

Return type:

float

epsilon()
Returns:

the value of epsilon

Return type:

float

eraseAllEvidence()

Removes all the evidence entered into the network.

Return type:

None

eraseAllTargets()

Clear all previously defined targets (marginal and joint targets).

As a result, no posterior can be computed (since we can only compute the posteriors of the marginal or joint targets that have been added by the user).

Return type:

None

eraseEvidence(*args)

Remove the evidence, if any, corresponding to the node Id or name.

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

Return type:

None

eraseTarget(*args)

Remove, if existing, the marginal target.

Parameters:

  • target (int) – a node Id

  • nodeName (int) – a node name

Raises:

  • pyAgrum.IndexError – If one of the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

Return type:

None

evidenceImpact(target, evs)

Create a pyAgrum.Potential for P(target|evs) (for all instanciation of target and evs)

Parameters:

  • target (set) – a set of targets ids or names.

  • evs (set) – a set of nodes ids or names.

Warning

if some evs are d-separated, they are not included in the Potential.

Returns:

a Potential for P(targets|evs)

Return type:

pyAgrum.Potential

hardEvidenceNodes()
Returns:

the set of nodes with hard evidence

Return type:

set

hasEvidence(*args)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if some node(s) (or the one in parameters) have received evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

hasHardEvidence(nodeName)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if node has received a hard evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

hasSoftEvidence(*args)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if node has received a soft evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

history()
Returns:

the scheme history

Return type:

tuple

Raises:

pyAgrum.OperationNotAllowed – If the scheme did not performed or if verbosity is set to false

isTarget(*args)
Parameters:

  • variable (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if variable is a (marginal) target

Return type:

bool

Raises:

  • pyAgrum.IndexError – If the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

makeInference()

Perform the heavy computations needed to compute the targets’ posteriors

In a Junction tree propagation scheme, for instance, the heavy computations are those of the messages sent in the JT. This is precisely what makeInference should compute. Later, the computations of the posteriors can be done ‘lightly’ by multiplying and projecting those messages.

Return type:

None

maxIter()
Returns:

the criterion on number of iterations

Return type:

int

maxTime()
Returns:

the timeout(in seconds)

Return type:

float

messageApproximationScheme()
Returns:

the approximation scheme message

Return type:

str

minEpsilonRate()
Returns:

the value of the minimal epsilon rate

Return type:

float

nbrEvidence()
Returns:

the number of evidence entered into the Bayesian network

Return type:

int

nbrHardEvidence()
Returns:

the number of hard evidence entered into the Bayesian network

Return type:

int

nbrIterations()
Returns:

the number of iterations

Return type:

int

nbrSoftEvidence()
Returns:

the number of soft evidence entered into the Bayesian network

Return type:

int

nbrTargets()
Returns:

the number of marginal targets

Return type:

int

periodSize()
Returns:

the number of samples between 2 stopping

Return type:

int

Raises:

pyAgrum.OutOfBounds – If p<1

posterior(*args)

Computes and returns the posterior of a node.

Parameters:

  • var (int) – the node Id of the node for which we need a posterior probability

  • nodeName (str) – the node name of the node for which we need a posterior probability

Returns:

a const ref to the posterior probability of the node

Return type:

pyAgrum.Potential

Raises:

pyAgrum.UndefinedElement – If an element of nodes is not in targets

setEpsilon(eps)
Parameters:

eps (float) – the epsilon we want to use

Raises:

pyAgrum.OutOfBounds – If eps<0

Return type:

None

setEvidence(evidces)

Erase all the evidences and apply addEvidence(key,value) for every pairs in evidces.

Parameters:

evidces (Dict[str,Union[int,str,List[float]]] or List[pyAgrum.Potential]) – a dict of “name:evidence” where name is a string (the name of the variable) and evidence is an integer (an index) or a string (a label) or a list of float (a likelihood).

Raises:

pyAgrum.InvalidArgument – If one value is not a value for the node pyAgrum.InvalidArgument If the size of a value is different from the domain side of the node pyAgrum.FatalError If one value is a vector of 0s pyAgrum.UndefinedElement If one node does not belong to the Bayesian network

setMaxIter(max)
Parameters:

max (int) – the maximum number of iteration

Raises:

pyAgrum.OutOfBounds – If max <= 1

Return type:

None

setMaxTime(timeout)
Parameters:

  • tiemout (float) – stopping criterion on timeout (in seconds)

  • timeout (float)

Raises:

pyAgrum.OutOfBounds – If timeout<=0.0

Return type:

None

setMinEpsilonRate(rate)
Parameters:

rate (float) – the minimal epsilon rate

Return type:

None

setPeriodSize(p)
Parameters:

p (int) – number of samples between 2 stopping

Raises:

pyAgrum.OutOfBounds – If p<1

Return type:

None

setTargets(targets)

Remove all the targets and add the ones in parameter.

Parameters:

targets (set) – a set of targets

Raises:

pyAgrum.UndefinedElement – If one target is not in the Bayes net

setVerbosity(v)
Parameters:

v (bool) – verbosity

Return type:

None

softEvidenceNodes()
Returns:

the set of nodes with soft evidence

Return type:

set

targets()
Returns:

the list of marginal targets

Return type:

list

property thisown

The membership flag

updateEvidence(evidces)

Apply chgEvidence(key,value) for every pairs in evidces (or addEvidence).

Parameters:

evidces (Dict[str,Union[int,str,List[float]]] or List[pyAgrum.Potential]) – a dict of “name:evidence” where name is a string (the name of the variable) and evidence is an integer (an index) or a string (a label) or a list of float (a likelihood).

Raises:
verbosity()
Returns:

True if the verbosity is enabled

Return type:

bool

Weighted Sampling for BN

class pyAgrum.WeightedSampling(bn)

Class used for Weighted sampling inference algorithm.

WeightedSampling(bn) -> WeightedSampling
Parameters:

  • bn (pyAgrum.BayesNet) – a Bayesian network

Parameters:

bn (IBayesNet)

BN()
Returns:

A constant reference over the IBayesNet referenced by this class.

Return type:

pyAgrum.IBayesNet

Raises:

pyAgrum.UndefinedElement – If no Bayes net has been assigned to the inference.

H(*args)
Parameters:

  • X (int) – a node Id

  • nodeName (str) – a node name

Returns:

the computed Shanon’s entropy of a node given the observation

Return type:

float

addAllTargets()

Add all the nodes as targets.

Return type:

None

addEvidence(*args)

Adds a new evidence on a node (might be soft or hard).

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

  • val – (int) a node value

  • val – (str) the label of the node value

  • vals (list) – a list of values

Raises:
Return type:

None

addTarget(*args)

Add a marginal target to the list of targets.

Parameters:

  • target (int) – a node Id

  • nodeName (str) – a node name

Raises:

pyAgrum.UndefinedElement – If target is not a NodeId in the Bayes net

Return type:

None

chgEvidence(*args)

Change the value of an already existing evidence on a node (might be soft or hard).

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

  • val (intstr) – a node value or the label of the node value

  • vals (List[float]) – a list of values

Raises:
Return type:

None

currentPosterior(*args)

Computes and returns the current posterior of a node.

Parameters:

  • var (int) – the node Id of the node for which we need a posterior probability

  • nodeName (str) – the node name of the node for which we need a posterior probability

Returns:

a const ref to the current posterior probability of the node

Return type:

pyAgrum.Potential

Raises:

UndefinedElement – If an element of nodes is not in targets

currentTime()
Returns:

get the current running time in second (float)

Return type:

float

epsilon()
Returns:

the value of epsilon

Return type:

float

eraseAllEvidence()

Removes all the evidence entered into the network.

Return type:

None

eraseAllTargets()

Clear all previously defined targets (marginal and joint targets).

As a result, no posterior can be computed (since we can only compute the posteriors of the marginal or joint targets that have been added by the user).

Return type:

None

eraseEvidence(*args)

Remove the evidence, if any, corresponding to the node Id or name.

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

Return type:

None

eraseTarget(*args)

Remove, if existing, the marginal target.

Parameters:

  • target (int) – a node Id

  • nodeName (int) – a node name

Raises:

  • pyAgrum.IndexError – If one of the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

Return type:

None

evidenceImpact(target, evs)

Create a pyAgrum.Potential for P(target|evs) (for all instanciation of target and evs)

Parameters:

  • target (set) – a set of targets ids or names.

  • evs (set) – a set of nodes ids or names.

Warning

if some evs are d-separated, they are not included in the Potential.

Returns:

a Potential for P(targets|evs)

Return type:

pyAgrum.Potential

hardEvidenceNodes()
Returns:

the set of nodes with hard evidence

Return type:

set

hasEvidence(*args)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if some node(s) (or the one in parameters) have received evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

hasHardEvidence(nodeName)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if node has received a hard evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

hasSoftEvidence(*args)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if node has received a soft evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

history()
Returns:

the scheme history

Return type:

tuple

Raises:

pyAgrum.OperationNotAllowed – If the scheme did not performed or if verbosity is set to false

isTarget(*args)
Parameters:

  • variable (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if variable is a (marginal) target

Return type:

bool

Raises:

  • pyAgrum.IndexError – If the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

makeInference()

Perform the heavy computations needed to compute the targets’ posteriors

In a Junction tree propagation scheme, for instance, the heavy computations are those of the messages sent in the JT. This is precisely what makeInference should compute. Later, the computations of the posteriors can be done ‘lightly’ by multiplying and projecting those messages.

Return type:

None

maxIter()
Returns:

the criterion on number of iterations

Return type:

int

maxTime()
Returns:

the timeout(in seconds)

Return type:

float

messageApproximationScheme()
Returns:

the approximation scheme message

Return type:

str

minEpsilonRate()
Returns:

the value of the minimal epsilon rate

Return type:

float

nbrEvidence()
Returns:

the number of evidence entered into the Bayesian network

Return type:

int

nbrHardEvidence()
Returns:

the number of hard evidence entered into the Bayesian network

Return type:

int

nbrIterations()
Returns:

the number of iterations

Return type:

int

nbrSoftEvidence()
Returns:

the number of soft evidence entered into the Bayesian network

Return type:

int

nbrTargets()
Returns:

the number of marginal targets

Return type:

int

periodSize()
Returns:

the number of samples between 2 stopping

Return type:

int

Raises:

pyAgrum.OutOfBounds – If p<1

posterior(*args)

Computes and returns the posterior of a node.

Parameters:

  • var (int) – the node Id of the node for which we need a posterior probability

  • nodeName (str) – the node name of the node for which we need a posterior probability

Returns:

a const ref to the posterior probability of the node

Return type:

pyAgrum.Potential

Raises:

pyAgrum.UndefinedElement – If an element of nodes is not in targets

setEpsilon(eps)
Parameters:

eps (float) – the epsilon we want to use

Raises:

pyAgrum.OutOfBounds – If eps<0

Return type:

None

setEvidence(evidces)

Erase all the evidences and apply addEvidence(key,value) for every pairs in evidces.

Parameters:

evidces (Dict[str,Union[int,str,List[float]]] or List[pyAgrum.Potential]) – a dict of “name:evidence” where name is a string (the name of the variable) and evidence is an integer (an index) or a string (a label) or a list of float (a likelihood).

Raises:

pyAgrum.InvalidArgument – If one value is not a value for the node pyAgrum.InvalidArgument If the size of a value is different from the domain side of the node pyAgrum.FatalError If one value is a vector of 0s pyAgrum.UndefinedElement If one node does not belong to the Bayesian network

setMaxIter(max)
Parameters:

max (int) – the maximum number of iteration

Raises:

pyAgrum.OutOfBounds – If max <= 1

Return type:

None

setMaxTime(timeout)
Parameters:

  • tiemout (float) – stopping criterion on timeout (in seconds)

  • timeout (float)

Raises:

pyAgrum.OutOfBounds – If timeout<=0.0

Return type:

None

setMinEpsilonRate(rate)
Parameters:

rate (float) – the minimal epsilon rate

Return type:

None

setPeriodSize(p)
Parameters:

p (int) – number of samples between 2 stopping

Raises:

pyAgrum.OutOfBounds – If p<1

Return type:

None

setTargets(targets)

Remove all the targets and add the ones in parameter.

Parameters:

targets (set) – a set of targets

Raises:

pyAgrum.UndefinedElement – If one target is not in the Bayes net

setVerbosity(v)
Parameters:

v (bool) – verbosity

Return type:

None

softEvidenceNodes()
Returns:

the set of nodes with soft evidence

Return type:

set

targets()
Returns:

the list of marginal targets

Return type:

list

property thisown

The membership flag

updateEvidence(evidces)

Apply chgEvidence(key,value) for every pairs in evidces (or addEvidence).

Parameters:

evidces (Dict[str,Union[int,str,List[float]]] or List[pyAgrum.Potential]) – a dict of “name:evidence” where name is a string (the name of the variable) and evidence is an integer (an index) or a string (a label) or a list of float (a likelihood).

Raises:
verbosity()
Returns:

True if the verbosity is enabled

Return type:

bool

Importance Sampling for BN

class pyAgrum.ImportanceSampling(bn)

Class used for inferences using the Importance Sampling algorithm.

ImportanceSampling(bn) -> ImportanceSampling
Parameters:

  • bn (pyAgrum.BayesNet) – a Bayesian network

Parameters:

bn (IBayesNet)

BN()
Returns:

A constant reference over the IBayesNet referenced by this class.

Return type:

pyAgrum.IBayesNet

Raises:

pyAgrum.UndefinedElement – If no Bayes net has been assigned to the inference.

H(*args)
Parameters:

  • X (int) – a node Id

  • nodeName (str) – a node name

Returns:

the computed Shanon’s entropy of a node given the observation

Return type:

float

addAllTargets()

Add all the nodes as targets.

Return type:

None

addEvidence(*args)

Adds a new evidence on a node (might be soft or hard).

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

  • val – (int) a node value

  • val – (str) the label of the node value

  • vals (list) – a list of values

Raises:
Return type:

None

addTarget(*args)

Add a marginal target to the list of targets.

Parameters:

  • target (int) – a node Id

  • nodeName (str) – a node name

Raises:

pyAgrum.UndefinedElement – If target is not a NodeId in the Bayes net

Return type:

None

chgEvidence(*args)

Change the value of an already existing evidence on a node (might be soft or hard).

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

  • val (intstr) – a node value or the label of the node value

  • vals (List[float]) – a list of values

Raises:
Return type:

None

currentPosterior(*args)

Computes and returns the current posterior of a node.

Parameters:

  • var (int) – the node Id of the node for which we need a posterior probability

  • nodeName (str) – the node name of the node for which we need a posterior probability

Returns:

a const ref to the current posterior probability of the node

Return type:

pyAgrum.Potential

Raises:

UndefinedElement – If an element of nodes is not in targets

currentTime()
Returns:

get the current running time in second (float)

Return type:

float

epsilon()
Returns:

the value of epsilon

Return type:

float

eraseAllEvidence()

Removes all the evidence entered into the network.

Return type:

None

eraseAllTargets()

Clear all previously defined targets (marginal and joint targets).

As a result, no posterior can be computed (since we can only compute the posteriors of the marginal or joint targets that have been added by the user).

Return type:

None

eraseEvidence(*args)

Remove the evidence, if any, corresponding to the node Id or name.

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

Return type:

None

eraseTarget(*args)

Remove, if existing, the marginal target.

Parameters:

  • target (int) – a node Id

  • nodeName (int) – a node name

Raises:

  • pyAgrum.IndexError – If one of the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

Return type:

None

evidenceImpact(target, evs)

Create a pyAgrum.Potential for P(target|evs) (for all instanciation of target and evs)

Parameters:

  • target (set) – a set of targets ids or names.

  • evs (set) – a set of nodes ids or names.

Warning

if some evs are d-separated, they are not included in the Potential.

Returns:

a Potential for P(targets|evs)

Return type:

pyAgrum.Potential

hardEvidenceNodes()
Returns:

the set of nodes with hard evidence

Return type:

set

hasEvidence(*args)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if some node(s) (or the one in parameters) have received evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

hasHardEvidence(nodeName)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if node has received a hard evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

hasSoftEvidence(*args)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if node has received a soft evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

history()
Returns:

the scheme history

Return type:

tuple

Raises:

pyAgrum.OperationNotAllowed – If the scheme did not performed or if verbosity is set to false

isTarget(*args)
Parameters:

  • variable (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if variable is a (marginal) target

Return type:

bool

Raises:

  • pyAgrum.IndexError – If the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

makeInference()

Perform the heavy computations needed to compute the targets’ posteriors

In a Junction tree propagation scheme, for instance, the heavy computations are those of the messages sent in the JT. This is precisely what makeInference should compute. Later, the computations of the posteriors can be done ‘lightly’ by multiplying and projecting those messages.

Return type:

None

maxIter()
Returns:

the criterion on number of iterations

Return type:

int

maxTime()
Returns:

the timeout(in seconds)

Return type:

float

messageApproximationScheme()
Returns:

the approximation scheme message

Return type:

str

minEpsilonRate()
Returns:

the value of the minimal epsilon rate

Return type:

float

nbrEvidence()
Returns:

the number of evidence entered into the Bayesian network

Return type:

int

nbrHardEvidence()
Returns:

the number of hard evidence entered into the Bayesian network

Return type:

int

nbrIterations()
Returns:

the number of iterations

Return type:

int

nbrSoftEvidence()
Returns:

the number of soft evidence entered into the Bayesian network

Return type:

int

nbrTargets()
Returns:

the number of marginal targets

Return type:

int

periodSize()
Returns:

the number of samples between 2 stopping

Return type:

int

Raises:

pyAgrum.OutOfBounds – If p<1

posterior(*args)

Computes and returns the posterior of a node.

Parameters:

  • var (int) – the node Id of the node for which we need a posterior probability

  • nodeName (str) – the node name of the node for which we need a posterior probability

Returns:

a const ref to the posterior probability of the node

Return type:

pyAgrum.Potential

Raises:

pyAgrum.UndefinedElement – If an element of nodes is not in targets

setEpsilon(eps)
Parameters:

eps (float) – the epsilon we want to use

Raises:

pyAgrum.OutOfBounds – If eps<0

Return type:

None

setEvidence(evidces)

Erase all the evidences and apply addEvidence(key,value) for every pairs in evidces.

Parameters:

evidces (Dict[str,Union[int,str,List[float]]] or List[pyAgrum.Potential]) – a dict of “name:evidence” where name is a string (the name of the variable) and evidence is an integer (an index) or a string (a label) or a list of float (a likelihood).

Raises:

pyAgrum.InvalidArgument – If one value is not a value for the node pyAgrum.InvalidArgument If the size of a value is different from the domain side of the node pyAgrum.FatalError If one value is a vector of 0s pyAgrum.UndefinedElement If one node does not belong to the Bayesian network

setMaxIter(max)
Parameters:

max (int) – the maximum number of iteration

Raises:

pyAgrum.OutOfBounds – If max <= 1

Return type:

None

setMaxTime(timeout)
Parameters:

  • tiemout (float) – stopping criterion on timeout (in seconds)

  • timeout (float)

Raises:

pyAgrum.OutOfBounds – If timeout<=0.0

Return type:

None

setMinEpsilonRate(rate)
Parameters:

rate (float) – the minimal epsilon rate

Return type:

None

setPeriodSize(p)
Parameters:

p (int) – number of samples between 2 stopping

Raises:

pyAgrum.OutOfBounds – If p<1

Return type:

None

setTargets(targets)

Remove all the targets and add the ones in parameter.

Parameters:

targets (set) – a set of targets

Raises:

pyAgrum.UndefinedElement – If one target is not in the Bayes net

setVerbosity(v)
Parameters:

v (bool) – verbosity

Return type:

None

softEvidenceNodes()
Returns:

the set of nodes with soft evidence

Return type:

set

targets()
Returns:

the list of marginal targets

Return type:

list

property thisown

The membership flag

updateEvidence(evidces)

Apply chgEvidence(key,value) for every pairs in evidces (or addEvidence).

Parameters:

evidces (Dict[str,Union[int,str,List[float]]] or List[pyAgrum.Potential]) – a dict of “name:evidence” where name is a string (the name of the variable) and evidence is an integer (an index) or a string (a label) or a list of float (a likelihood).

Raises:
verbosity()
Returns:

True if the verbosity is enabled

Return type:

bool

Loopy sampling

Pure Loopy Gibbs Sampling

class pyAgrum.LoopyGibbsSampling(bn)

Class used for inferences using a loopy version of importance sampling.

LoopyImportanceSampling(bn) -> LoopyImportanceSampling
Parameters:

  • bn (pyAgrum.BayesNet) – a Bayesian network

Parameters:

bn (IBayesNet)

BN()
Returns:

A constant reference over the IBayesNet referenced by this class.

Return type:

pyAgrum.IBayesNet

Raises:

pyAgrum.UndefinedElement – If no Bayes net has been assigned to the inference.

H(*args)
Parameters:

  • X (int) – a node Id

  • nodeName (str) – a node name

Returns:

the computed Shanon’s entropy of a node given the observation

Return type:

float

addAllTargets()

Add all the nodes as targets.

Return type:

None

addEvidence(*args)

Adds a new evidence on a node (might be soft or hard).

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

  • val – (int) a node value

  • val – (str) the label of the node value

  • vals (list) – a list of values

Raises:
Return type:

None

addTarget(*args)

Add a marginal target to the list of targets.

Parameters:

  • target (int) – a node Id

  • nodeName (str) – a node name

Raises:

pyAgrum.UndefinedElement – If target is not a NodeId in the Bayes net

Return type:

None

burnIn()
Returns:

size of burn in on number of iteration

Return type:

int

chgEvidence(*args)

Change the value of an already existing evidence on a node (might be soft or hard).

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

  • val (intstr) – a node value or the label of the node value

  • vals (List[float]) – a list of values

Raises:
Return type:

None

currentPosterior(*args)

Computes and returns the current posterior of a node.

Parameters:

  • var (int) – the node Id of the node for which we need a posterior probability

  • nodeName (str) – the node name of the node for which we need a posterior probability

Returns:

a const ref to the current posterior probability of the node

Return type:

pyAgrum.Potential

Raises:

UndefinedElement – If an element of nodes is not in targets

currentTime()
Returns:

get the current running time in second (float)

Return type:

float

epsilon()
Returns:

the value of epsilon

Return type:

float

eraseAllEvidence()

Removes all the evidence entered into the network.

Return type:

None

eraseAllTargets()

Clear all previously defined targets (marginal and joint targets).

As a result, no posterior can be computed (since we can only compute the posteriors of the marginal or joint targets that have been added by the user).

Return type:

None

eraseEvidence(*args)

Remove the evidence, if any, corresponding to the node Id or name.

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

Return type:

None

eraseTarget(*args)

Remove, if existing, the marginal target.

Parameters:

  • target (int) – a node Id

  • nodeName (int) – a node name

Raises:

  • pyAgrum.IndexError – If one of the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

Return type:

None

evidenceImpact(target, evs)

Create a pyAgrum.Potential for P(target|evs) (for all instanciation of target and evs)

Parameters:

  • target (set) – a set of targets ids or names.

  • evs (set) – a set of nodes ids or names.

Warning

if some evs are d-separated, they are not included in the Potential.

Returns:

a Potential for P(targets|evs)

Return type:

pyAgrum.Potential

hardEvidenceNodes()
Returns:

the set of nodes with hard evidence

Return type:

set

hasEvidence(*args)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if some node(s) (or the one in parameters) have received evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

hasHardEvidence(nodeName)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if node has received a hard evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

hasSoftEvidence(*args)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if node has received a soft evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

history()
Returns:

the scheme history

Return type:

tuple

Raises:

pyAgrum.OperationNotAllowed – If the scheme did not performed or if verbosity is set to false

isDrawnAtRandom()
Returns:

True if variables are drawn at random

Return type:

bool

isTarget(*args)
Parameters:

  • variable (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if variable is a (marginal) target

Return type:

bool

Raises:

  • pyAgrum.IndexError – If the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

makeInference()

Perform the heavy computations needed to compute the targets’ posteriors

In a Junction tree propagation scheme, for instance, the heavy computations are those of the messages sent in the JT. This is precisely what makeInference should compute. Later, the computations of the posteriors can be done ‘lightly’ by multiplying and projecting those messages.

Return type:

None

makeInference_()
Return type:

None

maxIter()
Returns:

the criterion on number of iterations

Return type:

int

maxTime()
Returns:

the timeout(in seconds)

Return type:

float

messageApproximationScheme()
Returns:

the approximation scheme message

Return type:

str

minEpsilonRate()
Returns:

the value of the minimal epsilon rate

Return type:

float

nbrDrawnVar()
Returns:

the number of variable drawn at each iteration

Return type:

int

nbrEvidence()
Returns:

the number of evidence entered into the Bayesian network

Return type:

int

nbrHardEvidence()
Returns:

the number of hard evidence entered into the Bayesian network

Return type:

int

nbrIterations()
Returns:

the number of iterations

Return type:

int

nbrSoftEvidence()
Returns:

the number of soft evidence entered into the Bayesian network

Return type:

int

nbrTargets()
Returns:

the number of marginal targets

Return type:

int

periodSize()
Returns:

the number of samples between 2 stopping

Return type:

int

Raises:

pyAgrum.OutOfBounds – If p<1

posterior(*args)

Computes and returns the posterior of a node.

Parameters:

  • var (int) – the node Id of the node for which we need a posterior probability

  • nodeName (str) – the node name of the node for which we need a posterior probability

Returns:

a const ref to the posterior probability of the node

Return type:

pyAgrum.Potential

Raises:

pyAgrum.UndefinedElement – If an element of nodes is not in targets

setBurnIn(b)
Parameters:

b (int) – size of burn in on number of iteration

Return type:

None

setDrawnAtRandom(_atRandom)
Parameters:

_atRandom (bool) – indicates if variables should be drawn at random

Return type:

None

setEpsilon(eps)
Parameters:

eps (float) – the epsilon we want to use

Raises:

pyAgrum.OutOfBounds – If eps<0

Return type:

None

setEvidence(evidces)

Erase all the evidences and apply addEvidence(key,value) for every pairs in evidces.

Parameters:

evidces (Dict[str,Union[int,str,List[float]]] or List[pyAgrum.Potential]) – a dict of “name:evidence” where name is a string (the name of the variable) and evidence is an integer (an index) or a string (a label) or a list of float (a likelihood).

Raises:

pyAgrum.InvalidArgument – If one value is not a value for the node pyAgrum.InvalidArgument If the size of a value is different from the domain side of the node pyAgrum.FatalError If one value is a vector of 0s pyAgrum.UndefinedElement If one node does not belong to the Bayesian network

setMaxIter(max)
Parameters:

max (int) – the maximum number of iteration

Raises:

pyAgrum.OutOfBounds – If max <= 1

Return type:

None

setMaxTime(timeout)
Parameters:

  • tiemout (float) – stopping criterion on timeout (in seconds)

  • timeout (float)

Raises:

pyAgrum.OutOfBounds – If timeout<=0.0

Return type:

None

setMinEpsilonRate(rate)
Parameters:

rate (float) – the minimal epsilon rate

Return type:

None

setNbrDrawnVar(_nbr)
Parameters:

_nbr (int) – the number of variables to be drawn at each iteration

Return type:

None

setPeriodSize(p)
Parameters:

p (int) – number of samples between 2 stopping

Raises:

pyAgrum.OutOfBounds – If p<1

Return type:

None

setTargets(targets)

Remove all the targets and add the ones in parameter.

Parameters:

targets (set) – a set of targets

Raises:

pyAgrum.UndefinedElement – If one target is not in the Bayes net

setVerbosity(v)
Parameters:

v (bool) – verbosity

Return type:

None

setVirtualLBPSize(vlbpsize)
Parameters:

vlbpsize (float) – the size of the virtual LBP

Return type:

None

softEvidenceNodes()
Returns:

the set of nodes with soft evidence

Return type:

set

targets()
Returns:

the list of marginal targets

Return type:

list

property thisown

The membership flag

updateEvidence(evidces)

Apply chgEvidence(key,value) for every pairs in evidces (or addEvidence).

Parameters:

evidces (Dict[str,Union[int,str,List[float]]] or List[pyAgrum.Potential]) – a dict of “name:evidence” where name is a string (the name of the variable) and evidence is an integer (an index) or a string (a label) or a list of float (a likelihood).

Raises:
verbosity()
Returns:

True if the verbosity is enabled

Return type:

bool

Loopy Monte Carlo Sampling

class pyAgrum.LoopyMonteCarloSampling(bn)

Class used for inferences using a loopy version of importance sampling.

LoopyImportanceSampling(bn) -> LoopyImportanceSampling
Parameters:

  • bn (pyAgrum.BayesNet) – a Bayesian network

Parameters:

bn (IBayesNet)

BN()
Returns:

A constant reference over the IBayesNet referenced by this class.

Return type:

pyAgrum.IBayesNet

Raises:

pyAgrum.UndefinedElement – If no Bayes net has been assigned to the inference.

H(*args)
Parameters:

  • X (int) – a node Id

  • nodeName (str) – a node name

Returns:

the computed Shanon’s entropy of a node given the observation

Return type:

float

addAllTargets()

Add all the nodes as targets.

Return type:

None

addEvidence(*args)

Adds a new evidence on a node (might be soft or hard).

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

  • val – (int) a node value

  • val – (str) the label of the node value

  • vals (list) – a list of values

Raises:
Return type:

None

addTarget(*args)

Add a marginal target to the list of targets.

Parameters:

  • target (int) – a node Id

  • nodeName (str) – a node name

Raises:

pyAgrum.UndefinedElement – If target is not a NodeId in the Bayes net

Return type:

None

chgEvidence(*args)

Change the value of an already existing evidence on a node (might be soft or hard).

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

  • val (intstr) – a node value or the label of the node value

  • vals (List[float]) – a list of values

Raises:
Return type:

None

currentPosterior(*args)

Computes and returns the current posterior of a node.

Parameters:

  • var (int) – the node Id of the node for which we need a posterior probability

  • nodeName (str) – the node name of the node for which we need a posterior probability

Returns:

a const ref to the current posterior probability of the node

Return type:

pyAgrum.Potential

Raises:

UndefinedElement – If an element of nodes is not in targets

currentTime()
Returns:

get the current running time in second (float)

Return type:

float

epsilon()
Returns:

the value of epsilon

Return type:

float

eraseAllEvidence()

Removes all the evidence entered into the network.

Return type:

None

eraseAllTargets()

Clear all previously defined targets (marginal and joint targets).

As a result, no posterior can be computed (since we can only compute the posteriors of the marginal or joint targets that have been added by the user).

Return type:

None

eraseEvidence(*args)

Remove the evidence, if any, corresponding to the node Id or name.

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

Return type:

None

eraseTarget(*args)

Remove, if existing, the marginal target.

Parameters:

  • target (int) – a node Id

  • nodeName (int) – a node name

Raises:

  • pyAgrum.IndexError – If one of the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

Return type:

None

evidenceImpact(target, evs)

Create a pyAgrum.Potential for P(target|evs) (for all instanciation of target and evs)

Parameters:

  • target (set) – a set of targets ids or names.

  • evs (set) – a set of nodes ids or names.

Warning

if some evs are d-separated, they are not included in the Potential.

Returns:

a Potential for P(targets|evs)

Return type:

pyAgrum.Potential

hardEvidenceNodes()
Returns:

the set of nodes with hard evidence

Return type:

set

hasEvidence(*args)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if some node(s) (or the one in parameters) have received evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

hasHardEvidence(nodeName)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if node has received a hard evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

hasSoftEvidence(*args)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if node has received a soft evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

history()
Returns:

the scheme history

Return type:

tuple

Raises:

pyAgrum.OperationNotAllowed – If the scheme did not performed or if verbosity is set to false

isTarget(*args)
Parameters:

  • variable (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if variable is a (marginal) target

Return type:

bool

Raises:

  • pyAgrum.IndexError – If the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

makeInference()

Perform the heavy computations needed to compute the targets’ posteriors

In a Junction tree propagation scheme, for instance, the heavy computations are those of the messages sent in the JT. This is precisely what makeInference should compute. Later, the computations of the posteriors can be done ‘lightly’ by multiplying and projecting those messages.

Return type:

None

makeInference_()
Return type:

None

maxIter()
Returns:

the criterion on number of iterations

Return type:

int

maxTime()
Returns:

the timeout(in seconds)

Return type:

float

messageApproximationScheme()
Returns:

the approximation scheme message

Return type:

str

minEpsilonRate()
Returns:

the value of the minimal epsilon rate

Return type:

float

nbrEvidence()
Returns:

the number of evidence entered into the Bayesian network

Return type:

int

nbrHardEvidence()
Returns:

the number of hard evidence entered into the Bayesian network

Return type:

int

nbrIterations()
Returns:

the number of iterations

Return type:

int

nbrSoftEvidence()
Returns:

the number of soft evidence entered into the Bayesian network

Return type:

int

nbrTargets()
Returns:

the number of marginal targets

Return type:

int

periodSize()
Returns:

the number of samples between 2 stopping

Return type:

int

Raises:

pyAgrum.OutOfBounds – If p<1

posterior(*args)

Computes and returns the posterior of a node.

Parameters:

  • var (int) – the node Id of the node for which we need a posterior probability

  • nodeName (str) – the node name of the node for which we need a posterior probability

Returns:

a const ref to the posterior probability of the node

Return type:

pyAgrum.Potential

Raises:

pyAgrum.UndefinedElement – If an element of nodes is not in targets

setEpsilon(eps)
Parameters:

eps (float) – the epsilon we want to use

Raises:

pyAgrum.OutOfBounds – If eps<0

Return type:

None

setEvidence(evidces)

Erase all the evidences and apply addEvidence(key,value) for every pairs in evidces.

Parameters:

evidces (Dict[str,Union[int,str,List[float]]] or List[pyAgrum.Potential]) – a dict of “name:evidence” where name is a string (the name of the variable) and evidence is an integer (an index) or a string (a label) or a list of float (a likelihood).

Raises:

pyAgrum.InvalidArgument – If one value is not a value for the node pyAgrum.InvalidArgument If the size of a value is different from the domain side of the node pyAgrum.FatalError If one value is a vector of 0s pyAgrum.UndefinedElement If one node does not belong to the Bayesian network

setMaxIter(max)
Parameters:

max (int) – the maximum number of iteration

Raises:

pyAgrum.OutOfBounds – If max <= 1

Return type:

None

setMaxTime(timeout)
Parameters:

  • tiemout (float) – stopping criterion on timeout (in seconds)

  • timeout (float)

Raises:

pyAgrum.OutOfBounds – If timeout<=0.0

Return type:

None

setMinEpsilonRate(rate)
Parameters:

rate (float) – the minimal epsilon rate

Return type:

None

setPeriodSize(p)
Parameters:

p (int) – number of samples between 2 stopping

Raises:

pyAgrum.OutOfBounds – If p<1

Return type:

None

setTargets(targets)

Remove all the targets and add the ones in parameter.

Parameters:

targets (set) – a set of targets

Raises:

pyAgrum.UndefinedElement – If one target is not in the Bayes net

setVerbosity(v)
Parameters:

v (bool) – verbosity

Return type:

None

setVirtualLBPSize(vlbpsize)
Parameters:

vlbpsize (float) – the size of the virtual LBP

Return type:

None

softEvidenceNodes()
Returns:

the set of nodes with soft evidence

Return type:

set

targets()
Returns:

the list of marginal targets

Return type:

list

property thisown

The membership flag

updateEvidence(evidces)

Apply chgEvidence(key,value) for every pairs in evidces (or addEvidence).

Parameters:

evidces (Dict[str,Union[int,str,List[float]]] or List[pyAgrum.Potential]) – a dict of “name:evidence” where name is a string (the name of the variable) and evidence is an integer (an index) or a string (a label) or a list of float (a likelihood).

Raises:
verbosity()
Returns:

True if the verbosity is enabled

Return type:

bool

Loopy Weighted Sampling

class pyAgrum.LoopyWeightedSampling(bn)

Class used for inferences using a loopy version of importance sampling.

LoopyImportanceSampling(bn) -> LoopyImportanceSampling
Parameters:

  • bn (pyAgrum.BayesNet) – a Bayesian network

Parameters:

bn (IBayesNet)

BN()
Returns:

A constant reference over the IBayesNet referenced by this class.

Return type:

pyAgrum.IBayesNet

Raises:

pyAgrum.UndefinedElement – If no Bayes net has been assigned to the inference.

H(*args)
Parameters:

  • X (int) – a node Id

  • nodeName (str) – a node name

Returns:

the computed Shanon’s entropy of a node given the observation

Return type:

float

addAllTargets()

Add all the nodes as targets.

Return type:

None

addEvidence(*args)

Adds a new evidence on a node (might be soft or hard).

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

  • val – (int) a node value

  • val – (str) the label of the node value

  • vals (list) – a list of values

Raises:
Return type:

None

addTarget(*args)

Add a marginal target to the list of targets.

Parameters:

  • target (int) – a node Id

  • nodeName (str) – a node name

Raises:

pyAgrum.UndefinedElement – If target is not a NodeId in the Bayes net

Return type:

None

chgEvidence(*args)

Change the value of an already existing evidence on a node (might be soft or hard).

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

  • val (intstr) – a node value or the label of the node value

  • vals (List[float]) – a list of values

Raises:
Return type:

None

currentPosterior(*args)

Computes and returns the current posterior of a node.

Parameters:

  • var (int) – the node Id of the node for which we need a posterior probability

  • nodeName (str) – the node name of the node for which we need a posterior probability

Returns:

a const ref to the current posterior probability of the node

Return type:

pyAgrum.Potential

Raises:

UndefinedElement – If an element of nodes is not in targets

currentTime()
Returns:

get the current running time in second (float)

Return type:

float

epsilon()
Returns:

the value of epsilon

Return type:

float

eraseAllEvidence()

Removes all the evidence entered into the network.

Return type:

None

eraseAllTargets()

Clear all previously defined targets (marginal and joint targets).

As a result, no posterior can be computed (since we can only compute the posteriors of the marginal or joint targets that have been added by the user).

Return type:

None

eraseEvidence(*args)

Remove the evidence, if any, corresponding to the node Id or name.

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

Return type:

None

eraseTarget(*args)

Remove, if existing, the marginal target.

Parameters:

  • target (int) – a node Id

  • nodeName (int) – a node name

Raises:

  • pyAgrum.IndexError – If one of the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

Return type:

None

evidenceImpact(target, evs)

Create a pyAgrum.Potential for P(target|evs) (for all instanciation of target and evs)

Parameters:

  • target (set) – a set of targets ids or names.

  • evs (set) – a set of nodes ids or names.

Warning

if some evs are d-separated, they are not included in the Potential.

Returns:

a Potential for P(targets|evs)

Return type:

pyAgrum.Potential

hardEvidenceNodes()
Returns:

the set of nodes with hard evidence

Return type:

set

hasEvidence(*args)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if some node(s) (or the one in parameters) have received evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

hasHardEvidence(nodeName)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if node has received a hard evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

hasSoftEvidence(*args)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if node has received a soft evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

history()
Returns:

the scheme history

Return type:

tuple

Raises:

pyAgrum.OperationNotAllowed – If the scheme did not performed or if verbosity is set to false

isTarget(*args)
Parameters:

  • variable (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if variable is a (marginal) target

Return type:

bool

Raises:

  • pyAgrum.IndexError – If the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

makeInference()

Perform the heavy computations needed to compute the targets’ posteriors

In a Junction tree propagation scheme, for instance, the heavy computations are those of the messages sent in the JT. This is precisely what makeInference should compute. Later, the computations of the posteriors can be done ‘lightly’ by multiplying and projecting those messages.

Return type:

None

makeInference_()
Return type:

None

maxIter()
Returns:

the criterion on number of iterations

Return type:

int

maxTime()
Returns:

the timeout(in seconds)

Return type:

float

messageApproximationScheme()
Returns:

the approximation scheme message

Return type:

str

minEpsilonRate()
Returns:

the value of the minimal epsilon rate

Return type:

float

nbrEvidence()
Returns:

the number of evidence entered into the Bayesian network

Return type:

int

nbrHardEvidence()
Returns:

the number of hard evidence entered into the Bayesian network

Return type:

int

nbrIterations()
Returns:

the number of iterations

Return type:

int

nbrSoftEvidence()
Returns:

the number of soft evidence entered into the Bayesian network

Return type:

int

nbrTargets()
Returns:

the number of marginal targets

Return type:

int

periodSize()
Returns:

the number of samples between 2 stopping

Return type:

int

Raises:

pyAgrum.OutOfBounds – If p<1

posterior(*args)

Computes and returns the posterior of a node.

Parameters:

  • var (int) – the node Id of the node for which we need a posterior probability

  • nodeName (str) – the node name of the node for which we need a posterior probability

Returns:

a const ref to the posterior probability of the node

Return type:

pyAgrum.Potential

Raises:

pyAgrum.UndefinedElement – If an element of nodes is not in targets

setEpsilon(eps)
Parameters:

eps (float) – the epsilon we want to use

Raises:

pyAgrum.OutOfBounds – If eps<0

Return type:

None

setEvidence(evidces)

Erase all the evidences and apply addEvidence(key,value) for every pairs in evidces.

Parameters:

evidces (Dict[str,Union[int,str,List[float]]] or List[pyAgrum.Potential]) – a dict of “name:evidence” where name is a string (the name of the variable) and evidence is an integer (an index) or a string (a label) or a list of float (a likelihood).

Raises:

pyAgrum.InvalidArgument – If one value is not a value for the node pyAgrum.InvalidArgument If the size of a value is different from the domain side of the node pyAgrum.FatalError If one value is a vector of 0s pyAgrum.UndefinedElement If one node does not belong to the Bayesian network

setMaxIter(max)
Parameters:

max (int) – the maximum number of iteration

Raises:

pyAgrum.OutOfBounds – If max <= 1

Return type:

None

setMaxTime(timeout)
Parameters:

  • tiemout (float) – stopping criterion on timeout (in seconds)

  • timeout (float)

Raises:

pyAgrum.OutOfBounds – If timeout<=0.0

Return type:

None

setMinEpsilonRate(rate)
Parameters:

rate (float) – the minimal epsilon rate

Return type:

None

setPeriodSize(p)
Parameters:

p (int) – number of samples between 2 stopping

Raises:

pyAgrum.OutOfBounds – If p<1

Return type:

None

setTargets(targets)

Remove all the targets and add the ones in parameter.

Parameters:

targets (set) – a set of targets

Raises:

pyAgrum.UndefinedElement – If one target is not in the Bayes net

setVerbosity(v)
Parameters:

v (bool) – verbosity

Return type:

None

setVirtualLBPSize(vlbpsize)
Parameters:

vlbpsize (float) – the size of the virtual LBP

Return type:

None

softEvidenceNodes()
Returns:

the set of nodes with soft evidence

Return type:

set

targets()
Returns:

the list of marginal targets

Return type:

list

property thisown

The membership flag

updateEvidence(evidces)

Apply chgEvidence(key,value) for every pairs in evidces (or addEvidence).

Parameters:

evidces (Dict[str,Union[int,str,List[float]]] or List[pyAgrum.Potential]) – a dict of “name:evidence” where name is a string (the name of the variable) and evidence is an integer (an index) or a string (a label) or a list of float (a likelihood).

Raises:
verbosity()
Returns:

True if the verbosity is enabled

Return type:

bool

Loopy Importance Sampling

class pyAgrum.LoopyImportanceSampling(bn)

Class used for inferences using a loopy version of importance sampling.

LoopyImportanceSampling(bn) -> LoopyImportanceSampling
Parameters:

  • bn (pyAgrum.BayesNet) – a Bayesian network

Parameters:

bn (IBayesNet)

BN()
Returns:

A constant reference over the IBayesNet referenced by this class.

Return type:

pyAgrum.IBayesNet

Raises:

pyAgrum.UndefinedElement – If no Bayes net has been assigned to the inference.

H(*args)
Parameters:

  • X (int) – a node Id

  • nodeName (str) – a node name

Returns:

the computed Shanon’s entropy of a node given the observation

Return type:

float

addAllTargets()

Add all the nodes as targets.

Return type:

None

addEvidence(*args)

Adds a new evidence on a node (might be soft or hard).

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

  • val – (int) a node value

  • val – (str) the label of the node value

  • vals (list) – a list of values

Raises:
Return type:

None

addTarget(*args)

Add a marginal target to the list of targets.

Parameters:

  • target (int) – a node Id

  • nodeName (str) – a node name

Raises:

pyAgrum.UndefinedElement – If target is not a NodeId in the Bayes net

Return type:

None

chgEvidence(*args)

Change the value of an already existing evidence on a node (might be soft or hard).

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

  • val (intstr) – a node value or the label of the node value

  • vals (List[float]) – a list of values

Raises:
Return type:

None

currentPosterior(*args)

Computes and returns the current posterior of a node.

Parameters:

  • var (int) – the node Id of the node for which we need a posterior probability

  • nodeName (str) – the node name of the node for which we need a posterior probability

Returns:

a const ref to the current posterior probability of the node

Return type:

pyAgrum.Potential

Raises:

UndefinedElement – If an element of nodes is not in targets

currentTime()
Returns:

get the current running time in second (float)

Return type:

float

epsilon()
Returns:

the value of epsilon

Return type:

float

eraseAllEvidence()

Removes all the evidence entered into the network.

Return type:

None

eraseAllTargets()

Clear all previously defined targets (marginal and joint targets).

As a result, no posterior can be computed (since we can only compute the posteriors of the marginal or joint targets that have been added by the user).

Return type:

None

eraseEvidence(*args)

Remove the evidence, if any, corresponding to the node Id or name.

Parameters:

  • id (int) – a node Id

  • nodeName (int) – a node name

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

Return type:

None

eraseTarget(*args)

Remove, if existing, the marginal target.

Parameters:

  • target (int) – a node Id

  • nodeName (int) – a node name

Raises:

  • pyAgrum.IndexError – If one of the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

Return type:

None

evidenceImpact(target, evs)

Create a pyAgrum.Potential for P(target|evs) (for all instanciation of target and evs)

Parameters:

  • target (set) – a set of targets ids or names.

  • evs (set) – a set of nodes ids or names.

Warning

if some evs are d-separated, they are not included in the Potential.

Returns:

a Potential for P(targets|evs)

Return type:

pyAgrum.Potential

hardEvidenceNodes()
Returns:

the set of nodes with hard evidence

Return type:

set

hasEvidence(*args)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if some node(s) (or the one in parameters) have received evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

hasHardEvidence(nodeName)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if node has received a hard evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

hasSoftEvidence(*args)
Parameters:

  • id (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if node has received a soft evidence

Return type:

bool

Raises:

pyAgrum.IndexError – If the node does not belong to the Bayesian network

history()
Returns:

the scheme history

Return type:

tuple

Raises:

pyAgrum.OperationNotAllowed – If the scheme did not performed or if verbosity is set to false

isTarget(*args)
Parameters:

  • variable (int) – a node Id

  • nodeName (str) – a node name

Returns:

True if variable is a (marginal) target

Return type:

bool

Raises:

  • pyAgrum.IndexError – If the node does not belong to the Bayesian network

  • pyAgrum.UndefinedElement – If node Id is not in the Bayesian network

makeInference()

Perform the heavy computations needed to compute the targets’ posteriors

In a Junction tree propagation scheme, for instance, the heavy computations are those of the messages sent in the JT. This is precisely what makeInference should compute. Later, the computations of the posteriors can be done ‘lightly’ by multiplying and projecting those messages.

Return type:

None

makeInference_()
Return type:

None

maxIter()
Returns:

the criterion on number of iterations

Return type:

int

maxTime()
Returns:

the timeout(in seconds)

Return type:

float

messageApproximationScheme()
Returns:

the approximation scheme message

Return type:

str

minEpsilonRate()
Returns:

the value of the minimal epsilon rate

Return type:

float

nbrEvidence()
Returns:

the number of evidence entered into the Bayesian network

Return type:

int

nbrHardEvidence()
Returns:

the number of hard evidence entered into the Bayesian network

Return type:

int

nbrIterations()
Returns:

the number of iterations

Return type:

int

nbrSoftEvidence()
Returns:

the number of soft evidence entered into the Bayesian network

Return type:

int

nbrTargets()
Returns:

the number of marginal targets

Return type:

int

periodSize()
Returns:

the number of samples between 2 stopping

Return type:

int

Raises:

pyAgrum.OutOfBounds – If p<1

posterior(*args)

Computes and returns the posterior of a node.

Parameters:

  • var (int) – the node Id of the node for which we need a posterior probability

  • nodeName (str) – the node name of the node for which we need a posterior probability

Returns:

a const ref to the posterior probability of the node

Return type:

pyAgrum.Potential

Raises:

pyAgrum.UndefinedElement – If an element of nodes is not in targets

setEpsilon(eps)
Parameters:

eps (float) – the epsilon we want to use

Raises:

pyAgrum.OutOfBounds – If eps<0

Return type:

None

setEvidence(evidces)

Erase all the evidences and apply addEvidence(key,value) for every pairs in evidces.

Parameters:

evidces (Dict[str,Union[int,str,List[float]]] or List[pyAgrum.Potential]) – a dict of “name:evidence” where name is a string (the name of the variable) and evidence is an integer (an index) or a string (a label) or a list of float (a likelihood).

Raises:

pyAgrum.InvalidArgument – If one value is not a value for the node pyAgrum.InvalidArgument If the size of a value is different from the domain side of the node pyAgrum.FatalError If one value is a vector of 0s pyAgrum.UndefinedElement If one node does not belong to the Bayesian network

setMaxIter(max)
Parameters:

max (int) – the maximum number of iteration

Raises:

pyAgrum.OutOfBounds – If max <= 1

Return type:

None

setMaxTime(timeout)
Parameters:

  • tiemout (float) – stopping criterion on timeout (in seconds)

  • timeout (float)

Raises:

pyAgrum.OutOfBounds – If timeout<=0.0

Return type:

None

setMinEpsilonRate(rate)
Parameters:

rate (float) – the minimal epsilon rate

Return type:

None

setPeriodSize(p)
Parameters:

p (int) – number of samples between 2 stopping

Raises:

pyAgrum.OutOfBounds – If p<1

Return type:

None

setTargets(targets)

Remove all the targets and add the ones in parameter.

Parameters:

targets (set) – a set of targets

Raises:

pyAgrum.UndefinedElement – If one target is not in the Bayes net

setVerbosity(v)
Parameters:

v (bool) – verbosity

Return type:

None

setVirtualLBPSize(vlbpsize)
Parameters:

vlbpsize (float) – the size of the virtual LBP

Return type:

None

softEvidenceNodes()
Returns:

the set of nodes with soft evidence

Return type:

set

targets()
Returns:

the list of marginal targets

Return type:

list

property thisown

The membership flag

updateEvidence(evidces)

Apply chgEvidence(key,value) for every pairs in evidces (or addEvidence).

Parameters:

evidces (Dict[str,Union[int,str,List[float]]] or List[pyAgrum.Potential]) – a dict of “name:evidence” where name is a string (the name of the variable) and evidence is an integer (an index) or a string (a label) or a list of float (a likelihood).

Raises:
verbosity()
Returns:

True if the verbosity is enabled

Return type:

bool