How to add texture to fill colors in ggplot2

Question

I\'m currently using scale_brewer() for fill and these look beautiful in color (on screen and via color printer) but print relatively uniformly as greys when us

Answer 1

It might be useful to create a dummy data frame whose contours correspond to "textures" and then use geom_contour. Here is my example:

library(ggplot2)

eg = expand.grid(R1 = seq(0,1,by=0.01), R2 = seq(0,1,by=0.01))
     eg$importance = (eg$R1+eg$R2)/2

  ggplot(eg , aes(x = R1, y = R2)) +
  geom_raster(aes(fill = importance), interpolate=TRUE) +
  scale_fill_gradient2(low="white", high="gray20", limits=c(0,1)) +
  theme_classic()+
  geom_contour(bins=5,aes(z=importance), color="black", size=0.6)+
  coord_fixed(ratio = 1, xlim=c(0,1),ylim=c(0,1))

And here is the result: shaded plot with lines

(the lines should be smoothed)