R/get_previous_node_indices.R

In GeertPostma/pathmodelr: Generalised Path Modeling Package for R

#' Gets the indices of the previous nodes in a connection matrix given a node_index
#'
#' Gets the integer indices of the previous nodes given a connection_matrix and a
#' starting index.
#'
#' @param connection_matrix A matrix where the non zero elements what
#'   connections exist. The rows indicate the node where the edge is going to,
#'   and the columns indicates the node where the edge is coming from.
#' @param node_index a number indicating of which node the type is being
#'   determined.
#' @return A list of indices of all previous level nodes
get_previous_node_indices <- function(connection_matrix, node_index){

  result <- (1:dim(connection_matrix)[1])[connection_matrix[node_index, ] == 1]
}