2d color gradient plot in R

Question

I want to produce a 2d color gradient rectangle like the ones in the picture below on the right hand side. How can I do this in R? Using colorRamp or RCol

Answer 1

you may try this and see result plot

rotate <- function(x) t(apply(x, 2, rev))
n <- 3
library(grid)
mm <- tcrossprod(seq(1,0,length.out = n))
tmp1 <- sapply(col2rgb("orange")/255, function(x) 1-mm*(1-x))
tmp2 <- sapply(col2rgb("cyan")/255, function(x) 1-rotate(mm)*(1-x))
tmp3 <- sapply(col2rgb("purple")/255, function(x) 1-rotate(rotate(mm))*(1-x))
tmp4 <- sapply(col2rgb("grey")/255, function(x) 1-rotate(rotate(rotate(mm)))*(1-x))

tmp <- (tmp1*tmp2*tmp3*tmp4)
grid.raster(matrix(rgb(tmp), nrow = n))

result plot < click it to see