R/filled_legend.R

In fawda123/CTDplot: Plot CTD water quality data along an estuarine axis

#' Plot legend from a contour plot
#'
#' Plot only the legend from a contour plot
#'
#' @inheritParams graphics::filled.contour
#' @param y numeric same as \code{x}
#' @param frame.plot logical for frame
#'
#' @details This function was taken from the filled.legend script at \url{http://wiki.cbr.washington.edu/qerm/index.php/R/Contour_Plots}.  The following was taken directly from original script:
#'
#' Modification of filled.contour by Carey McGilliard and Bridget Ferris designed to just plot the legend.
#'
#' @export
filled_legend <-
  function (x = seq(0, 1, length.out = nrow(z)), y = seq(0, 1,
    length.out = ncol(z)), z, xlim = range(x, finite = TRUE),
    ylim = range(y, finite = TRUE), zlim = range(z, finite = TRUE),
    levels = pretty(zlim, nlevels), nlevels = 20, color.palette = cm.colors,
    col = color.palette(length(levels) - 1), plot.title, plot.axes,
    key.title, key.axes, asp = NA, xaxs = "i", yaxs = "i", las = 1,
    axes = TRUE, frame.plot = axes, ...)
{

    if (missing(z)) {
        if (!missing(x)) {
            if (is.list(x)) {
                z <- x$z
                y <- x$y
                x <- x$x
            }
            else {
                z <- x
                x <- seq.int(0, 1, length.out = nrow(z))
            }
        }
        else stop("no 'z' matrix specified")
    }
    else if (is.list(x)) {
        y <- x$y
        x <- x$x
    }
    if (any(diff(x) <= 0) || any(diff(y) <= 0))
        stop("increasing 'x' and 'y' values expected")

    plot.window(xlim = c(0, 1), ylim = range(levels), xaxs = "i",
        yaxs = "i")
    rect(0, levels[-length(levels)], 1, levels[-1L], col = col)
    if (missing(key.axes)) {
        if (axes)
            axis(4)
    }
    else key.axes
    box()
}