Question

I’ve got the following data which I can visualize like this

A = matrix(c(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 2, 1, 5, 6, 3, 4, 9, 10, 7, 8, 12, 11, 3, 5, 1, 7, 2, 9, 4, 11, 6, 12, 8, 10, 4, 6, 7, 8, 9, 10, 11, 1, 12, 2, 3, 5, 5, 3, 2, 9, 1, 7, 6, 12, 4, 11, 10, 8, 6, 4, 9, 10, 7, 8, 12, 2, 11, 1, 5, 3, 7, 9, 4, 11, 6, 12, 8, 3, 10, 5, 1, 2, 8, 10, 11, 1, 12, 2, 3, 4, 5, 6, 7, 9, 9, 7, 6, 12, 4, 11, 10, 5, 8, 3, 2, 1, 10, 8, 12, 2, 11, 1, 5, 6, 3, 4, 9, 7, 11, 12, 8, 3, 10, 5, 1, 7, 2, 9, 4, 6, 12, 11, 10, 5, 8, 3, 2, 9, 1, 7, 6, 4),nrow=12,ncol=12,byrow=TRUE)
require(plotrix)
color2D.matplot(A)

(A could be any square matrix of whole numbers)

I need to make it display with random colors which aren’t too similar. Here’s an example of what I am trying to achieve:

I’ve been unable to get randomized colors to work. Is matplot the function for this? Can anyone show me how to randomize the colors?

Answer 1

Per @DWin’s comment, try:

plot(NULL, type= "n", xlim = c(1,ncol(A)), ylim = c(1, nrow(A)), xlab = "column", ylab = "row",
  main = "HCL colors, pseudo-random hue, scaled chroma and luminance")
rect(col(A)-.5,row(A)-.5,col(A)+.5,row(A)+.5,
     col = hcl(h = round(runif(length(A))*360), c = 60*A/max(A)+20, l = 60*A/max(A)+20)
    )

I guessed that you still wanted the values in your matrix to still determine the ‘darkness’ of the colors, as was the case in the grayscale image. The only thing random here is the hue- i.e. a randomly picked angle from a color wheel.