R/compare_mat.R

In rCarto/flows: Selections on Flow Matrices, Statistics on Selected Flows, Map and Graph Visualisations

#' @title Comparison of two matrices
#' @name compare_mat
#' @description Compares two matrices of same dimension, with same column and
#' row names.
#' @param mat1 A square matrix of flows.
#' @param mat2 A square matrix of flows.
#' @param digits	An integer indicating the number of decimal places to be used
#' when printing the data.frame in the console (see \link{round}).
#' @return A data.frame that provides statistics on differences
#' between mat1 and mat2: absdiff are the
#' absolute differences and reldiff are the relative differences (in percent).
#' @examples
#' # # Import data
#' nav <- read.csv(system.file("csv/nav.csv", package = "flows"))
#' mat <- prepare_mat(x = nav, i = "i", j = "j", fij = "fij")
#' # Remove the matrix diagonal
#' diag(mat) <- 0
#'
#' # Select the first flows
#' flowSel1 <- select_flows(mat = mat, method = "nfirst", k = 1)
#'
#' # Select flows greater than 2000
#' flowSel2 <- select_flows(mat = mat, method = "xfirst", k = 2000)
#'
#' # Combine selections
#' flowSel <- mat * flowSel1 * flowSel2
#'
#' # Compare flow matrices
#' compare_mat(mat1 = mat, mat2 = flowSel, digits = 1)
#' @export
compare_mat <- function(mat1, mat2, digits = 0) {
  x1 <- stat_mat(mat1, output = "none", verbose = FALSE)
  x2 <- stat_mat(mat2, output = "none", verbose = FALSE)
  compdf <- data.frame(
    mat1 = c(
      x1$nblinks, x1$sumflows, x1$connectcompx,
      x1$min, x1$Q1, x1$median, x1$Q3,
      x1$max, x1$mean, x1$sd
    ),
    mat2 = c(
      x2$nblinks, x2$sumflows, x2$connectcompx,
      x2$min, x2$Q1, x2$median, x2$Q3,
      x2$max, x2$mean, x2$sd
    ),
    row.names = c(
      "nblinks", "sumflows", "connectcompx",
      "min", "Q1", "median", "Q3",
      "max", "mean", "sd"
    )
  )

  compdf$absdiff <- abs(compdf$mat1 - compdf$mat2)
  compdf[4:10, "absdiff"] <- NA
  compdf$reldiff <- abs(compdf$mat1 - compdf$mat2) / compdf$mat1 * 100
  compdf[3:10, "reldiff"] <- NA

  print(round(compdf, digits))
  return(invisible(compdf))
}