R/create_confmatrix.R

In NLeSC/EEG-epilepsy-diagnosis: Epilepsy detection with emotiv data

#' Create confusion matrix
#'
#' Creates an NxN confusion matrix for a binary classification and its reference values
#'
#' @param predicted predicted class
#' @param reference reference class
#' 
#' @return confmat confusion matrix
#' @author Vincent T van Hees
#' @examples set.seed(21)
#' reference <- make.names(round(runif(n=10,min=0,max=0.8),digits=0))
#' set.seed(23)
#' predicted <- make.names(round(runif(n=10,min=0,max=0.8),digits=0))
#' confusionmatrix <- create_confmatrix(reference, predicted)
#' @export
#' 
create_confmatrix = function(predicted,reference) {
  makeconfmatsquare = function(x) { # function to turn confusion 1x2 or 2x1 table() matrix into a square matrix
    ihave = which(colnames(x) == rownames(x))
    if (length(ihave) == 0) {
      print(colnames(x))
      print(rownames(x))
    }
    if (ncol(x) > nrow(x)) {
      if (ihave == 2) {
        x = rbind(c(0,0),x)
      } else {
        x = rbind(x,c(0,0))
      }
    } else if (ncol(x) < nrow(x)) {
      if (ihave == 2) {
        x = cbind(c(0,0),x)
      } else {
        x = cbind(x,c(0,0))
      }
    }
    return(x)
  }
  confmat = makeconfmatsquare(table(predicted,reference))
  dimnames(confmat)[[1]] = c("X1","X2")
  dimnames(confmat)[[2]] = c("X1","X2")
  return(confmat)
}