Source code for dit.multivariate.interaction_information

The interaction information is a form of multivariate information.

import numpy as np

from ..helpers import normalize_rvs
from ..utils import unitful
from .coinformation import coinformation

__all__ = [

[docs]@unitful def interaction_information(dist, rvs=None, crvs=None, rv_mode=None): """ Calculates the interaction information. Parameters ---------- dist : Distribution The distribution from which the interaction information is calculated. rvs : list, None The indexes of the random variable used to calculate the interaction information between. If None, then the interaction information is calculated over all random variables. crvs : list, None The indexes of the random variables to condition on. If None, then no variables are condition on. rv_mode : str, None Specifies how to interpret `rvs` and `crvs`. Valid options are: {'indices', 'names'}. If equal to 'indices', then the elements of `crvs` and `rvs` are interpreted as random variable indices. If equal to 'names', the the elements are interpreted as random variable names. If `None`, then the value of `dist._rv_mode` is consulted, which defaults to 'indices'. Returns ------- II : float The interaction information. Raises ------ ditException Raised if `dist` is not a joint distribution or if `rvs` or `crvs` contain non-existant random variables. """ rvs, crvs, rv_mode = normalize_rvs(dist, rvs, crvs, rv_mode) II = (-1)**len(rvs) * coinformation(dist, rvs, crvs, rv_mode) if np.isclose(II, 0): II = 0.0 return II