#' @param thresh real, threshold to say a variable is relevant, by default = 1e-8
#' @param eps threshold to say that EM algorithm has converged
#' @param ncores Number or cores for parallel execution (1 to disable)
+#' @param fast boolean to enable or not the C function call
#'
#' @return a list of outputs, for each lambda in grid: selected,Rho,Pi
#'