R/scatterdens.R

In swfscMisc: Miscellaneous Functions for Southwest Fisheries Science Center

#' @name scatterdens
#' @title Scatter Plot with Density Margins
#' @description Produce a scatter plot with a histogram or density plot in 
#'   the margins
#' 
#' @param x,y vectors of points to plot.
#' @param xlab,ylab labels for x and y axes.
#' @param dens.frac fraction of screen to be taken up by density plots on margins.
#' @param ... Arguments to be passed to \link{plot}.
#' 
#' @author Eric Archer \email{eric.archer@@noaa.gov}
#' 
#' @references Original code by 
#' \href{https://sas-and-r.blogspot.co.uk/2011/06/example-841-scatterplot-with-marginal.html}{Ken Kleiman}
#' 
#' @examples
#' x <- rnorm(100)
#' y <- rlnorm(100)
#' op <- par(ask = TRUE)
#' scatterdens(x, y, xlab = "x", ylab = "y")
#' par(op)
#' 
#' @importFrom stats density
#' @importFrom graphics layout par plot hist barplot
#' @export
#' 
scatterdens <- function(x, y, dens.frac = 1/5, ...) {
  zones <- matrix(c(2,0,1,3), ncol = 2, byrow = TRUE)
  layout(zones, widths = c(1 - dens.frac, dens.frac), heights = c(dens.frac, 1 - dens.frac))
  x.dens <- density(x)
  y.dens <- density(y)
  top <- max(x.dens$y, y.dens$y)
  op <- par(mar = c(3, 3, 1, 1))
  plot(x, y, main = "", ...)
  par(mar = c(0, 3, 1, 1))
  plot(x.dens, axes = FALSE, ylim = c(0, top), main = "")
  par(mar = c(3, 0, 1, 1))
  plot(y.dens$y, y.dens$x, type = "l", axes = FALSE, xlim = c(0, top))
  par(op)
}

#' @rdname scatterdens
#' @export
#' 
scatterhist <- function(x, y, xlab = "", ylab = "", dens.frac = 1/5, ...) {
  zones <- matrix(c(2,0,1,3), ncol = 2, byrow = TRUE)
  layout(zones, widths = c(1 - dens.frac, dens.frac), heights = c(dens.frac, 1 - dens.frac))
  xhist <- hist(x, plot = FALSE)
  yhist <- hist(y, plot = FALSE)
  top <- max(c(xhist$counts, yhist$counts))
  op <- par(mar = c(3, 3, 1, 1))
  plot(x, y, main = "", ...)
  par(mar = c(0, 3, 1, 1))
  barplot(xhist$counts, axes = FALSE, ylim = c(0, top), space = 0)
  par(mar = c(3, 0, 1, 1))
  barplot(yhist$counts, axes = FALSE, xlim = c(0, top), space = 0, horiz = TRUE)
  par(op)
}