nltk.ConditionalProbDist
¶
-
class
nltk.
ConditionalProbDist
(cfdist, probdist_factory, *factory_args, **factory_kw_args)[source]¶ A conditional probability distribution modeling the experiments that were used to generate a conditional frequency distribution. A ConditionalProbDist is constructed from a
ConditionalFreqDist
and aProbDist
factory:- The
ConditionalFreqDist
specifies the frequency distribution for each condition. - The
ProbDist
factory is a function that takes a condition’s frequency distribution, and returns its probability distribution. AProbDist
class’s name (such asMLEProbDist
orHeldoutProbDist
) can be used to specify that class’s constructor.
The first argument to the
ProbDist
factory is the frequency distribution that it should model; and the remaining arguments are specified by thefactory_args
parameter to theConditionalProbDist
constructor. For example, the following code constructs aConditionalProbDist
, where the probability distribution for each condition is anELEProbDist
with 10 bins:>>> from nltk.corpus import brown >>> from nltk.probability import ConditionalFreqDist >>> from nltk.probability import ConditionalProbDist, ELEProbDist >>> cfdist = ConditionalFreqDist(brown.tagged_words()[:5000]) >>> cpdist = ConditionalProbDist(cfdist, ELEProbDist, 10) >>> cpdist['passed'].max() 'VBD' >>> cpdist['passed'].prob('VBD') 0.423...
- The
Methods¶
__init__ (cfdist, probdist_factory, ...) |
Construct a new conditional probability distribution, based on the given conditional frequency distribution and ProbDist factory. |
clear (() -> None. Remove all items from D.) |
|
conditions () |
Return a list of the conditions that are represented by this ConditionalProbDist . |
copy (() -> a shallow copy of D) |
|
fromkeys (...) |
v defaults to None. |
get ((k[,d]) -> D[k] if k in D, ...) |
|
has_key ((k) -> True if D has a key k, else False) |
|
items (() -> list of D’s (key, value) pairs, ...) |
|
iteritems (() -> an iterator over the (key, ...) |
|
iterkeys (() -> an iterator over the keys of D) |
|
itervalues (...) |
|
keys (() -> list of D’s keys) |
|
pop ((k[,d]) -> v, ...) |
If key is not found, d is returned if given, otherwise KeyError is raised |
popitem (() -> (k, v), ...) |
2-tuple; but raise KeyError if D is empty. |
setdefault ((k[,d]) -> D.get(k,d), ...) |
|
unicode_repr () |
Return a string representation of this ConditionalProbDist . |
update (([E, ...) |
If E present and has a .keys() method, does: for k in E: D[k] = E[k] |
values (() -> list of D’s values) |
|
viewitems (...) |
|
viewkeys (...) |
|
viewvalues (...) |