Kernel estimate for (Conditional) Mutual Information

Estimates Mutual Information and Conditional Mutual Information between continuous random variables

Mutual information I(X,Y) measures the degree of dependence (in terms of probability theory) between two random variables X and Y. Is is non-negative and equal to zero when X and Y are mutually independent. Conditional mutual information I(X,Y|Z) is the expected value of I(X,Y) given the value of Z.

Data is first copula-transformed, then marginal and joint probability distributions are estimated using Gaussian kernels.

Useful in construction and verification of gene regulatory networks (see e.g. http://www.biomedcentral.com/1471-2105/7/S1/S7) given gene expression data. This quantity is robust and can trace non-linear dependencies and indirect interactions in data.