R/gPlots.R

In arulesViz: Visualizing Association Rules and Frequent Itemsets

#######################################################################
# arulesViz - Visualizing Association Rules and Frequent Itemsets
# Copyright (C) 2021 Michael Hahsler
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.


## simple image plot using grid

gTitle <- function(
    main,
    height = unit(4, "lines"),
    gp = gpar(fontface = "bold", cex = 1.2),
    name = NULL) {
  pushViewport(viewport(
    y = 1,
    height = height,
    just = c("top"),
    name = name
  ))
  grid.text(main,
    gp = gp
  )
  upViewport(1)
}

gImage <- function(
    m,
    xScale = NULL,
    yScale = NULL,
    xlab = NULL,
    ylab = NULL,
    name = NULL,
    axes = TRUE,
    gp = gpar(),
    ...) {
  df <- which(!is.na(m), arr.ind = TRUE)
  y <- df[, 1] - 1L
  x <- df[, 2] - 1L
  z <- as.vector(m[!is.na(m)])


  if (is.null(xScale)) {
    width <- 1
    xScale <- c(1, ncol(m) + 1L) - .5
    x <- x + .5
  } else {
    width <- diff(xScale) / ncol(m)
    xS <- c(xScale[1] + width / 2, xScale[2] - width / 2) - width / 2
    x <- map(x, xS)
  }

  if (is.null(yScale)) {
    height <- 1
    yScale <- c(0, nrow(m)) + .5
    y <- y + .5
  } else {
    height <- diff(yScale) / nrow(m)
    yS <- c(yScale[1] + height / 2, yScale[2] - height / 2) - height / 2
    y <- map(y, yS)
  }

  ## create viewport
  vp <- viewport(
    xscale = xScale,
    yscale = yScale,
    default.units = "native",
    name = name
  )
  pushViewport(vp)

  ## draw squares
  grid.rect(
    x = x,
    y = y,
    width,
    height,
    gp = gpar(fill = z, col = 0),
    just = c("left", "bottom"),
    default.units = "native"
  )

  ## border and axes
  gp_border <- gp
  gp_border$fill <- "transparent"
  grid.rect(
    x = 0,
    y = 0,
    width = 1,
    height = 1,
    just = c("left", "bottom"),
    default.units = "npc",
    gp = gp_border
  )

  if (is.logical(axes) && axes) {
    grid.xaxis(gp = gp)
    grid.yaxis(gp = gp)
  }

  if (is.character(axes) && axes == "integer") {
    grid.xaxis(gp = gp, at = 1:ncol(m))
    grid.yaxis(gp = gp, at = 1:nrow(m))
  }

  ## labels
  if (!is.null(xlab)) {
    grid.text(xlab, 0.5, unit(-3, "lines"))
  }
  if (!is.null(ylab)) {
    grid.text(ylab, unit(-3, "lines"), 0.5, rot = 90)
  }

  upViewport(1)
}


gScatterplot <- function(
    x,
    y = NULL,
    xlim = NULL,
    ylim = NULL,
    xlab = "x",
    ylab = "y",
    col = "black",
    cex = 1,
    pch = 1,
    alpha = NULL,
    new = TRUE,
    main = "Scatterplot",
    name = NULL,
    gp = gpar()) {
  if (is(x, "matrix") || is(x, "data.frame")) {
    y <- x[, 2]
    x <- x[, 1]
  }

  ## scale and filter points
  if (is.null(xlim)) {
    xlim <- range(x, na.rm = TRUE)
  } else {
    x[x < xlim[1] | x > xlim[2]] <- NA
  }
  if (is.null(ylim)) {
    ylim <- range(y, na.rm = TRUE)
  } else {
    y[y < ylim[1] | y > ylim[2]] <- NA
  }

  ## handle a single vaule for lim
  if (diff(xlim) == 0) {
    xlim <- xlim * c(0.5, 1.5)
  }
  if (diff(ylim) == 0) {
    ylim <- ylim * c(0.5, 1.5)
  }

  ## make plotting region 5% larger
  width <- diff(xlim)
  height <- diff(ylim)
  xlim[1] <- xlim[1] - width * 0.025
  xlim[2] <- xlim[2] + width * 0.025
  ylim[1] <- ylim[1] - height * 0.025
  ylim[2] <- ylim[2] + height * 0.025

  ## new plot
  if (new) {
    grid.newpage()
    pushViewport(plotViewport())
    grid.text(main,
      .5,
      unit(1, "npc") + unit(2, "lines"),
      gp = gpar(fontface = "bold", cex = 1.2)
    )
  }

  pushViewport(viewport(
    clip = FALSE,
    xscale = xlim,
    yscale = ylim,
    name = name
  ))
  ## axes
  grid.xaxis()
  grid.yaxis()
  grid.text(xlab, .5, unit(-3, "lines"))
  grid.text(ylab, unit(-3.5, "lines"), .5, rot = 90)

  ## points
  grid.points(x,
    y,
    pch = pch,
    gp = gpar(
      col = col,
      fill = col,
      alpha = alpha,
      cex = cex
    )
  )

  ## box
  grid.rect(
    x = 0,
    y = 0,
    width = 1,
    height = 1,
    just = c("left", "bottom"),
    default.units = "npc",
    gp = gpar(fill = "transparent")
  )

  upViewport(1)
  if (new) {
    upViewport(1)
  }
}

gColorkey <- function(
    range,
    col,
    label = NULL,
    name = "colorkey",
    gp = gpar()) {
  n <- length(col)
  height <- diff(range) / n
  ys <-
    seq(range[1] + height / 2, range[2] - height / 2, length.out = n)

  vp <- viewport(
    xscale = c(0, 1),
    yscale = c(range[1] + height / 2, range[2] + height / 2),
    default.units = "native",
    name = name
  )
  pushViewport(vp)

  ## col
  gp_col <- gp
  gp_col$col <- 0
  gp_col$fill <- col
  grid.rect(
    x = 0,
    y = ys,
    width = 1,
    height = height,
    just = c("left", "bottom"),
    default.units = "native",
    gp = gp_col
  )


  ## box
  gp_border <- gp
  gp_border$fill <- "transparent"
  grid.rect(
    x = 0,
    y = 0,
    width = 1,
    height = 1,
    just = c("left", "bottom"),
    default.units = "npc",
    gp = gp_border
  )

  grid.yaxis(gp = gp, main = FALSE)

  ## label
  if (!is.null(label)) {
    grid.text(label, 0.5, unit(-1, "lines"))
  }

  upViewport(1)
}

gParacoords <- function(
    m,
    discreteNames = NULL,
    col = NULL,
    lwd = NULL,
    arrowPos = NULL,
    xlab = NULL,
    name = NULL,
    gp = gpar(),
    gp_lines = gpar()) {
  if (is.null(col)) {
    col <- 1
  }
  if (length(col) == 1) {
    col <- rep(col, nrow(m))
  }
  if (is.null(lwd)) {
    lwd <- 1
  }
  if (length(lwd) == 1) {
    lwd <- rep(lwd, nrow(m))
  }
  if (is.null(arrowPos)) {
    arrowPos <- 0
  }
  if (length(arrowPos) == 1) {
    arrowPos <- rep(arrowPos, nrow(m))
  }

  arrow_type <- arrow(angle = 15)

  if (is.null(discreteNames)) {
    # leftSpace <- unit(3, "lines")
    yscale <- range(as.numeric(m), na.rm = TRUE)
  } else {
    # leftSpace <- max(stringWidth(discreteNames))
    yscale <- c(.5, length(discreteNames) + .5)
  }

  pushViewport(viewport(
    xscale = c(.5, ncol(m) + .5),
    yscale = yscale,
    default.units = "native",
    gp = gp,
    name = name
  ))

  ## axes
  grid.xaxis(at = 1:ncol(m), label = colnames(m))
  if (is.null(discreteNames)) {
    grid.yaxis()
  } else {
    grid.yaxis(at = 1:length(discreteNames), label = discreteNames)
  }
  if (!is.null(xlab)) {
    grid.text(xlab, .5, unit(-3, "lines"))
  }

  ## box
  grid.rect(
    x = 0,
    y = 0,
    width = 1,
    height = 1,
    just = c("left", "bottom"),
    default.units = "npc",
    gp = gpar(fill = "transparent")
  )

  ## grid
  gp_grid <- gpar(col = "gray", lty = 3)
  for (i in 1:ncol(m)) {
    grid.lines(
      x = c(i, i),
      y = unit(c(0, 1), "npc"),
      default.units = "native",
      gp = gp_grid
    )
  }

  ## draw lines
  for (i in 1:nrow(m)) {
    line <- m[i, ]
    gp_lines$lwd <- lwd[i]
    gp_lines$col <- col[i]
    arr <- arrowPos[i]

    for (j in 1:length(line)) {
      grid.lines(
        y = line[j:(j + 1L)],
        x = c(j, j + 1L),
        default.units = "native",
        gp = gp_lines,
        arrow = if ((j + 1L) == arr) {
          arrow_type
        } else {
          NULL
        }
      )
    }
  }

  upViewport(1)
}