Module dist :: Class DDist

Class DDist

Discrete distribution represented as a dictionary. Can be sparse, in the sense that elements that are not explicitly contained in the dictionary are assumed to have zero probability.

Instance Methods

__init__(self, dictionary)

dictCopy(self)
Returns: A copy of the dictionary for this distribution.

prob(self, elt)
Returns: the probability associated with elt

support(self)
Returns: A list (in arbitrary order) of the elements of this distribution with non-zero probabability.

__repr__(self)

__str__(self)

draw(self)
Returns: a randomly drawn element from the distribution

maxProbElt(self)
Returns: The element in this domain with maximum probability

marginalizeOut(self, index)
Returns: DDist on all the rest of the variables

conditionOnVar(self, index, value)
Returns: new distribution, conditioned on variable i having value value, and with variable i removed from all of the elements (it's redundant at this point).

Instance Variables
	d Dictionary whose keys are elements of the domain and values are their probabilities.

Method Details

dictCopy(self)

Returns:: A copy of the dictionary for this distribution.

prob(self, elt)

Parameters:

elt - an element of the domain of this distribution (does not need to be explicitly represented in the dictionary; in fact, for any element not in the dictionary, we return probability 0 without error.)

Returns:

the probability associated with elt

support(self)

Returns:: A list (in arbitrary order) of the elements of this distribution with non-zero probabability.

draw(self)

Returns:: a randomly drawn element from the distribution

maxProbElt(self)

Returns:: The element in this domain with maximum probability

marginalizeOut(self, index)

Parameters:

index - index of a random variable to sum out of the distribution

Returns:

DDist on all the rest of the variables

conditionOnVar(self, index, value)

Parameters:

index - index of a variable in the joint distribution
value - value of that variable

Returns:

new distribution, conditioned on variable i having value value, and with variable i removed from all of the elements (it's redundant at this point).