R/mplot_raster.R

In egenn/rtemis: Machine Learning and Visualization

# mplot_raster.R
# ::rtemis::
# 2019 E.D. Gennatas www.lambdamd.org

#' Plot Array as Raster Image
#'
#' Plots 2D (grayscale) or 3D (color) array as Raster Image
#'
#' @param x Array, 2D or 3D: Input describing grayscale or color image in RGB space
#' @param mono Logical: If TRUE, plot as grayscale using `mono.fn` to convert RGB to grayscale. Default = FALSE
#' @param mono.fn Function: Apply this function to the array to convert to 2D for grayscale plotting. Default = mean
#' @param bg Color: Background color (around the plotted image when window proportions do not match image). Default = "gray10"
#' @param par.reset Logical: If TRUE, reset par settings before exiting. Default = TRUE
#' @param verbose Logical: If TRUE, print messages to console. Default = TRUE
#' @author E.D. Gennatas
#' @export
#' @examples
#' \dontrun{
#' img <- imager::load.image("https://www.r-project.org/logo/Rlogo.png")
#' mplot_raster(img)
#' }

mplot_raster <- function(x,
                         max.value = max(x),
                         mar = NULL,
                         main = NULL,
                         main.line = 0,
                         main.side = 3,
                         main.col = "#ffffff",
                         main.adj = 0,
                         main.font = 2,
                         mono = FALSE,
                         mono.fn = mean,
                         bg = "gray10",
                         par.set = TRUE,
                         par.reset = TRUE,
                         verbose = TRUE) {

  if (dim(x)[3] > 3) {
    .dim <- dim(x)
    if (verbose) msg20("Input has dimensions ", .dim[1], "x", .dim[2], "x", .dim[3],
                      "; Using first 3")
    x <- x[, , seq(3)]
  }

  if (mono) x <- apply(x, c(1, 2), mono.fn)

  if (!par.set) par.reset <- FALSE
  if (par.reset) {
    par.orig <- par(no.readonly = TRUE)
    on.exit(par(par.orig))
  }
  if (is.null(mar)) {
    mar <- if (is.null(main)) rep(0, 4) else c(0, 0, 1, 0)
  }
  if (par.set) {
    par(pty = "s", bg = bg, mar = mar, oma = c(0, 0, 0, 0), xaxs = "i", yaxs = "i")
  }
  plot(NULL, NULL, xlim = c(0, 100), ylim = c(0, 100), axes = FALSE, ann = FALSE)
  if (!is.null(main)) {
    mtext(main, main.side, line = main.line, col = main.col, adj = main.adj,
          font = main.font)
  }
  rasterImage(x/max.value, 0, 0, 100, 100)

} # rtemis::mplot_raster