_matutils – Compiled extension for math utils

gensim._matutils.digamma

Digamma function for positive floats, using _digamma().

Parameters

x (float) – Positive value.

Returns

Digamma(x).

Return type

float

gensim._matutils.dirichlet_expectation(alpha)

Expected value of log(theta) where theta is drawn from a Dirichlet distribution. Using dirichlet_expectation_1d() or dirichlet_expectation_2d().

Parameters

alpha (numpy.ndarray) – Dirichlet parameter 2d matrix or 1d vector, if 2d - each row is treated as a separate parameter vector, supports float16, float32 and float64.

Returns

Log of expected values, dimension same as alpha.ndim.

Return type

numpy.ndarray

gensim._matutils.dirichlet_expectation_1d(alpha)

Expected value of log(theta) where theta is drawn from a Dirichlet distribution. Using _dirichlet_expectation_1d().

Parameters

alpha (numpy.ndarray) – Dirichlet parameter 1d vector, supports float16, float32 and float64.

Returns

Log of expected values, 1d vector.

Return type

numpy.ndarray

gensim._matutils.dirichlet_expectation_2d(alpha)

Expected value of log(theta) where theta is drawn from a Dirichlet distribution. Using _dirichlet_expectation_2d().

Parameters

alpha (numpy.ndarray) – Dirichlet parameter 2d matrix, each row is treated as a separate parameter vector, supports float16, float32 and float64.

Returns

Log of expected values, 2d matrix.

Return type

numpy.ndarray

gensim._matutils.logsumexp(x)

Log of sum of exponentials, using _logsumexp_2d().

Parameters

x (numpy.ndarray) – Input 2d matrix, supports float16, float32 and float64.

Returns

log of sum of exponentials of elements in x.

Return type

float

Warning

By performance reasons, doesn’t support NaNs or 1d, 3d, etc arrays like scipy.special.logsumexp().

gensim._matutils.mean_absolute_difference(a, b)

Mean absolute difference between two arrays, using _mean_absolute_difference().

Parameters
  • a (numpy.ndarray) – Input 1d array, supports float16, float32 and float64.

  • b (numpy.ndarray) – Input 1d array, supports float16, float32 and float64.

Returns

mean(abs(a - b)).

Return type

float