Potentials and Instantiation

Instantiation

class pyAgrum.Instantiation(*args)

Class for assigning/browsing values to tuples of discrete variables.

Instantiation is designed to assign values to tuples of variables and to efficiently loop over values of subsets of variables.

Available ructors:

Instantiation() -> Instantiation

Instantiation(aI) -> Instantiation

Parameters:aI (pyAgrum.Instantiation) – The Instantiation we copy
Returns:
  • pyAgrum.Instantiation – An empty tuple or a copy of the one in parameters
  • Instantiation is subscriptable therefore values can be easily accessed/modified.

Examples

>>> ## Access the value of A in an instantiation aI
>>> valueOfA = aI['A']
>>> ## Modify the value
>>> aI['A'] = newValueOfA
add(self, v)

Adds a new variable in the Instantiation.

Parameters:v (pyAgrum.DiscreteVariable) – The new variable added to the Instantiation
Raises:DuplicateElement – If the variable is already in this Instantiation
chgVal(self, v, newval)

chgVal(self, v, newval) -> Instantiation chgVal(self, varPos, newval) -> Instantiation chgVal(self, var, newval) -> Instantiation chgVal(self, var, newval) -> Instantiation

Assign newval to v (or to the variable at position varPos) in the Instantiation.

Parameters:
  • v (pyAgrum.DiscreteVariable or string) – The variable whose value is assigned (or its name)
  • varPos (int) – The index of the variable whose value is assigned in the tuple of variables of the Instantiation
  • newval (int or string) – The index of the value assigned (or its name)
Returns:

The modified instantiation

Return type:

pyAgrum.Instantiation

Raises:
  • NotFound – If variable v does not belong to the instantiation.
  • OutOfBound – If newval is not a possible value for the variable.
clear(self)

Erase all variables from an Instantiation.

contains(self, v)

contains(self, v) -> bool

Indicates whether a given variable belongs to the Instantiation.

Parameters:v (pyAgrum.DiscreteVariable) – The variable for which the test is made.
Returns:True if the variable is in the Instantiation.
Return type:bool
dec(self)

Operator –.

decIn(self, i)

Operator – for the variables in i.

Parameters:i (pyAgrum.Instantiation) – The set of variables to decrement in this Instantiation
decNotVar(self, v)

Operator – for vars which are not v.

Parameters:v (pyAgrum.DiscreteVariable) – The variable not to decrement in this Instantiation.
decOut(self, i)

Operator – for the variables not in i.

Parameters:i (pyAgrum.Instantiation) – The set of variables to not decrement in this Instantiation.
decVar(self, v)

Operator – for variable v only.

Parameters:v (pyAgrum.DiscreteVariable) – The variable to decrement in this Instantiation.
Raises:NotFound – If variable v does not belong to the Instantiation.
domainSize(self)
Returns:The product of the variable’s domain size in the Instantiation.
Return type:int
empty(self)
Returns:True if the instantiation is empty.
Return type:bool
end(self)
Returns:True if the Instantiation reached the end.
Return type:bool
erase(self, v)
Parameters:v (pyAgrum.DiscreteVariable) – The variable to be removed from this Instantiation.
Raises:NotFound – If v does not belong to this Instantiation.
fromdict(self, dict)

Change the values in an instantiation from a dict (variable_name:value) where value can be a position (int) or a label (string).

If a variable_name does not occur in the instantiation, nothing is done.

Warning

OutOfBounds raised if a value cannot be found.

hamming(self)
Returns:the hamming distance of this instantiation.
Return type:int
inOverflow(self)
Returns:True if the current value of the tuple is correct
Return type:bool
inc(self)

Operator ++.

incIn(self, i)

Operator ++ for the variables in i.

Parameters:i (pyAgrum.Instantiation) – The set of variables to increment in this Instantiation.
incNotVar(self, v)

Operator ++ for vars which are not v.

Parameters:v (pyAgrum.DiscreteVariable) – The variable not to increment in this Instantiation.
incOut(self, i)

Operator ++ for the variables not in i.

Parameters:i (Instantiation) – The set of variable to not increment in this Instantiation.
incVar(self, v)

Operator ++ for variable v only.

Parameters:v (pyAgrum.DiscreteVariable) – The variable to increment in this Instantiation.
Raises:NotFound – If variable v does not belong to the Instantiation.
nbrDim(self)
Returns:The number of variables in the Instantiation.
Return type:int
pos(self, v)
Returns:the position of the variable v.
Return type:int
Parameters:v (pyAgrum.DiscreteVariable) – the variable for which its position is return.
Raises:NotFound – If v does not belong to the instantiation.
rend(self)
Returns:True if the Instantiation reached the rend.
Return type:bool
reorder(self, v)

reorder(self, i)

Reorder vars of this instantiation giving the order in v (or i).

Parameters:
  • i (pyAgrum.Instantiation) – The sequence of variables with which to reorder this Instantiation.
  • v (list) – The new order of variables for this Instantiation.
setFirst(self)

Assign the first values to the tuple of the Instantiation.

setFirstIn(self, i)

Assign the first values in the Instantiation for the variables in i.

Parameters:i (pyAgrum.Instantiation) – The variables to which their first value is assigned in this Instantiation.
setFirstNotVar(self, v)

Assign the first values to variables different of v.

Parameters:v (pyAgrum.DiscreteVariable) – The variable that will not be set to its first value in this Instantiation.
setFirstOut(self, i)

Assign the first values in the Instantiation for the variables not in i.

Parameters:i (pyAgrum.Instantiation) – The variable that will not be set to their first value in this Instantiation.
setFirstVar(self, v)

Assign the first value in the Instantiation for var v.

Parameters:v (pyAgrum.DiscreteVariable) – The variable that will be set to its first value in this Instantiation.
setLast(self)

Assign the last values in the Instantiation.

setLastIn(self, i)

Assign the last values in the Instantiation for the variables in i.

Parameters:i (pyAgrum.Instantiation) – The variables to which their last value is assigned in this Instantiation.
setLastNotVar(self, v)

Assign the last values to variables different of v.

Parameters:v (pyAgrum.DiscreteVariable) – The variable that will not be set to its last value in this Instantiation.
setLastOut(self, i)

Assign the last values in the Instantiation for the variables not in i.

Parameters:i (pyAgrum.Instantiation) – The variables that will not be set to their last value in this Instantiation.
setLastVar(self, v)

Assign the last value in the Instantiation for var v.

Parameters:v (pyAgrum.DiscreteVariable) – The variable that will be set to its last value in this Instantiation.
setVals(self, i)

Assign the values from i in the Instantiation.

Parameters:i (pyAgrum.Instantiation) – An Instantiation in which the new values are searched
Returns:a reference to the instantiation
Return type:pyAgrum.Instantiation
todict(self, withLabels=False)

todict(self) -> PyObject *

Create a dict (variable_name:value) from an instantiation

Parameters:withLabels (boolean) – The value will be a label (string) if True. It will be a position (int) if False.
Returns:The dictionary
Return type:Dict
unsetEnd(self)

Alias for unsetOverflow().

unsetOverflow(self)

Removes the flag overflow.

val(self, i)

val(self, var) -> int

Parameters:
  • i (int) – The index of the variable.
  • var (pyAgrum.DiscreteVariable) – The variable the value of which we wish to know
Returns:

the current value of the variable.

Return type:

int

Raises:

NotFound – If the element cannot be found.

variable(self, i)

variable(self, name) -> DiscreteVariable

Parameters:i (int) – The index of the variable
Returns:the variable at position i in the tuple.
Return type:pyAgrum.DiscreteVariable
Raises:NotFound – If the element cannot be found.
variablesSequence(self)
Returns:the sequence of DiscreteVariable of this instantiation.
Return type:List

Potential

pyAgrum.Potential

alias of pyAgrum.pyAgrum.Potential_double

class pyAgrum.pyAgrum.Potential_double(*args)

Class representing a potential.

Available ructors:

Potential() -> Potential

Potential(src) -> Potential

Parameters:src (pyAgrum.Potential) – The Potential to copy
Returns:The new Potential
Return type:pyAgrum.Potential
KL(self, p)

C heck the compatibility and compute the Kullback-Leibler divergence between the potential and.

Parameters:

p (pyAgrum.Potential) – the potential from which we want to calculate the divergence.

Returns:

The value of the divergence

Return type:

float

Raises:
  • gum.InvalidArgument – If p is not compatible with the potential (dimension, variables)
  • gum.FatalError – If a zero is found in p or the potential and not in the other.
abs(self)

Apply abs on every element of the container

Returns:a reference to the modified potential.
Return type:pyAgrum.Potential
add(self, v)

Add a discrete variable to the potential.

Parameters:v (pyAgrum.DiscreteVariable) – the var to be added
Raises:gum.Error – If DiscretizedVariable added with no Tick.
argmax(self)
argmin(self)
contains(self, v)
Parameters:v (pyAgrum.Potential) – a DiscreteVariable.
Returns:True if the var is in the potential
Return type:bool
draw(self)

draw a value using the potential as a probability table.

Returns:the index of the drawn value
Return type:int
empty(self)
Returns:Returns true if no variable is in the potential.
Return type:bool
entropy(self)
Returns:the entropy of the potential
Return type:double
extract(self, inst)

extract(self, dict) -> Potential

create a new Potential extracted from self given a partial instantiation.

Parameters:
  • inst (pyAgrum.instantiation) – a partial instantiation
  • dict (dict) – a dictionnary containing discrete variables (?)
Returns:

the new Potential

Return type:

pyAgrum.Potential

fill(v)

Deprecated method in pyAgrum>0.12.0. See fillWith instead.

fillWith(self, src)

fillWith(self, src, mapSrc) -> Potential fillWith(self, v) -> Potential fillWith(self, v) -> Potential

findAll(self, v)
get(self, i)
Parameters:i (pyAgrum.Instantiation) – an Instantiation
Returns:the value of the instantiation
Return type:double
isNonZeroMap(self)
Returns:a boolean-like potential using the predicate isNonZero
Return type:pyAgrum.Potential
margMaxIn(self, varnames)

Projection using max as operation.

Parameters:varnames (set) – the set of vars to keep
Returns:the projected Potential
Return type:pyAgrum.Potential
margMaxOut(self, varnames)

Projection using max as operation.

Parameters:varnames (set) – the set of vars to eliminate
Returns:the projected Potential
Return type:pyAgrum.Potential
Raises:gum.InvalidArgument – If varnames contains only one variable that does not exist in the Potential
margMinIn(self, varnames)

Projection using min as operation.

Parameters:varnames (set) – the set of vars to keep
Returns:the projected Potential
Return type:pyAgrum.Potential
margMinOut(self, varnames)

Projection using min as operation.

Parameters:varnames (set) – the set of vars to eliminate
Returns:the projected Potential
Return type:pyAgrum.Potential

Warning

InvalidArgument raised if varnames contains only one variable that does not exist in the Potential

margProdIn(self, varnames)

Projection using multiplication as operation.

Parameters:varnames (set) – the set of vars to keep
Returns:the projected Potential
Return type:pyAgrum.Potential
margProdOut(self, varnames)

Projection using multiplication as operation.

Parameters:varnames (set) – the set of vars to eliminate
Returns:the projected Potential
Return type:pyAgrum.Potential
Raises:gum.InvalidArgument – If varnames contains only one variable that does not exist in the Potential
margSumIn(self, varnames)

Projection using sum as operation.

Parameters:varnames (set) – the set of vars to keep
Returns:the projected Potential
Return type:pyAgrum.Potential
margSumOut(self, varnames)

Projection using sum as operation.

Parameters:varnames (set) – the set of vars to eliminate
Returns:the projected Potential
Return type:pyAgrum.Potential
Raises:gum.InvalidArgument – If varnames contains only one variable that does not exist in the Potential
max(self)
Returns:the maximum of all elements in the Potential
Return type:double
maxNonOne(self)
Returns:the maximum of non one elements in the Potential
Return type:double
Raises:gum.NotFound – If all value == 1.0
min(self)
Returns:the min of all elements in the Potential
Return type:double
minNonZero(self)
Returns:the min of non zero elements in the Potential
Return type:double
Raises:gum.NotFound – If all value == 0.0
nbrDim(self)
Returns:the number of vars in the multidimensional container.
Return type:int
newFactory(self)

Erase the Potential content and create a new empty one.

Returns:a reference to the new Potential
Return type:pyAgrum.Potential
normalize(self)

Normalize the Potential (do nothing if sum is 0)

Returns:a reference to the normalized Potential
Return type:pyAgrum.Potential
normalizeAsCPT(self)

Normalize the Potential as a CPT

Returns:a reference to the normalized Potential
Return type:pyAgrum.Potential
Raises:gum.FatalError – If some distribution sums to 0
pos(self, v)
Parameters:v (pyAgrum.DiscreteVariable) – The variable for which the index is returned.
Returns:
Return type:Returns the index of a variable.
Raises:gum.NotFound – If v is not in this multidimensional matrix.
product(self)
Returns:the product of all elements in the Potential
Return type:double
putFirst(self, varname)
Parameters:v (pyAgrum.DiscreteVariable) – The variable for which the index should be 0.
Returns:a reference to the modified potential
Return type:pyAgrum.Potential
Raises:gum.InvalidArgument – If the var is not in the potential
remove(self, var)
Parameters:v (pyAgrum.DiscreteVariable) – The variable to be removed
Returns:a reference to the modified potential
Return type:pyAgrum.Potential

Warning

IndexError raised if the var is not in the potential

reorganize(self, vars)

reorganize(self, varnames) -> Potential

Create a new Potential with another order.

Returns:varnames – a list of the var names in the new order
Return type:list
Returns:a reference to the modified potential
Return type:pyAgrum.Potential
scale(self, v)

Create a new potential multiplied by v.

Parameters:v (double) – a multiplier
Returns:
Return type:a reference to the modified potential
set(self, i, value)

Change the value pointed by i

Parameters:
  • i (pyAgrum.Instantiation) – The Instantiation to be changed
  • value (double) – The new value of the Instantiation
sq(self)

Square all the values in the Potential

sum(self)
Returns:the sum of all elements in the Potential
Return type:double
toarray()
Returns:the potential as an array
Return type:array
tolist()
Returns:the potential as a list
Return type:list
translate(self, v)

Create a new potential added with v.

Parameters:v (double) – The value to be added
Returns:
Return type:a reference to the modified potential
var_dims
Returns:a list containing the dimensions of each variables in the potential
Return type:list
var_names
Returns:a list containing the name of each variables in the potential
Return type:list
variable(self, i)

variable(self, name) -> DiscreteVariable

Parameters:i (int) – An index of this multidimensional matrix.
Returns:
Return type:the varible at the ith index
Raises:gum.NotFound – If i does not reference a variable in this multidimensional matrix.
variablesSequence()
Returns:a list containing the sequence of variables
Return type:list