R/cor2mi.R

In wyguo/RLowPC: Inference of co-expression gene network using relevance low order partial correlation from large scale expression data

#' Convert correlation matrix to MI matrix
#'
#' The correlation \eqn{\rho_{ij}} between node \eqn{i} and \eqn{j} is converted into mutual information (MI) matrix by using equation [1]:
#' \deqn{MI=-\frac{1}{2} (1-\rho_{ij}^2)}
#' if the observation data is normal distributed.
#'
#' @param x a correlation matrix
#' @references
#' [1] Meyer PE, Kontos K, Lafitte F, Bontempi G: Information-theoretic inference of large transcriptional
#' regulatory networks. EURASIP J Bioinform Syst Biol 2007:79879.
#' @return \code{cor2mi} returns a mutual information matrix.
#' @export
cor2mi=function(x){
  mi=-0.5*log(1-x^2)
  return(mi)
}