[R] Recipe: Print a Color Sampler

[Gabor Grothendieck]

I have removed the dots, vectorized it and changed the
argument to the number points to be identified (default 0):

getColorName <- function(colorNumber) colors()[colorNumber]
printColorSampler <- function(n = 0) {
   i <- seq(colors())
   k <- ceiling(sqrt(length(i)))
   xy <- cbind(floor(i/k)*2, i %% k)
   plot(xy, type = "n", axes = FALSE, xlab = "", ylab = "")
   text(x+.5, y+.2, i, col = colors(), cex = 0.7)
   if (n > 0)
      colors()[identify(xy, n = n, labels = colors(), plot = FALSE)]
}
# test
printColorSampler(0)
printColorSampler(1)



On 10/22/06, Stefano Calza <calza at med.unibs.it> wrote:
> Thanks, might be very useful.
>
> I attached a slightly modified version that uses identify (whith an argument to choose if use it), to return the name of the colors on the panel. Left-click on the choosen colors, and right click to end.
>
> Stefano
>
>
> On Sun, Oct 22, 2006 at 12:51:19PM +0100, Ana Nelson wrote:
> <Ana>I wrote this to help me choose a suitable plot color. You can set the
> <Ana>value of pch to whichever type of point you are using in your plot,
> <Ana>and then you can see what the various colors will look like. When
> <Ana>this plot it stretched to A4/Letter landscape it prints quite nicely,
> <Ana>even though it will look very bunched up initially. I have only used
> <Ana>this on my own machine which runs Apple OSX 10.4.
> <Ana>
> <Ana>I included a getColorName() convenience function to retrieve the name
> <Ana>of the color from its position in the colors() array which is printed
> <Ana>next to the dot in the plot.
> <Ana>
> <Ana>printColorSampler <- function() {
> <Ana>     i <- 1
> <Ana>     pch <- 20
> <Ana>     l <- length(colors())
> <Ana>     k <- ceiling(sqrt(l))
> <Ana>
> <Ana>     plot(floor(i/k), i %% k, pch=pch, col=colors()[i], xlim=c(0,
> <Ana>k*2), ylim=c(0, k), axes=FALSE, xlab="", ylab="")
> <Ana>
> <Ana>     for (i in 2:length(colors())) {
> <Ana>           x <- floor(i/k)*2
> <Ana>           y <- i %% k
> <Ana>           col=colors()[i]
> <Ana>           points(x, y, pch=pch, col=col)
> <Ana>           text(x+0.5, y+0.2, i, col=col, cex=0.7)
> <Ana>     }
> <Ana>}
> <Ana>
> <Ana>getColorName <- function(colorNumber) {
> <Ana>     colors()[colorNumber]
> <Ana>}
> <Ana>
> <Ana>______________________________________________
> <Ana>R-help at stat.math.ethz.ch mailing list
> <Ana>https://stat.ethz.ch/mailman/listinfo/r-help
> <Ana>PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> <Ana>and provide commented, minimal, self-contained, reproducible code.
>
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
>
>
>