1

I have a raster stack of 5 rasters (invented examples here in s), and I would like to make two plots of the max and min value from this stack- this is fairly simple using max/ min (a). 

 r <- raster(nrows=10,ncols=100)
 r[] <- rnorm(1000)
 s <- stack(r,r,r,r,r) 
 a<-max(s, na.rm=T)
 plot(a)

However, what I want to do is plot but apply raster specific colours. So for example if the max value in a cell was from raster 3 in the stack, that cell in the plot would be coloured red, in the next cell the max value is from raster 5 then that would be green etc... Is there anyway of applying raster specific colours to such a raster stack plot?

I'm sure this is fairly simply, but I'm going around in circles. If anyone has got any ideas I would be very grateful.

lbusett
  • 5,801
  • 2
  • 24
  • 47
Arferion
  • 53
  • 4
  • Is there any way you can make this a [reproducible question](http://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example)? It's a little difficult speaking in generalities. – r2evans Feb 26 '17 at 21:03
  • thanks r2evans, generic example inserted. – Arferion Feb 26 '17 at 21:34

1 Answers1

1

You should use which.max instead of max to get which layer is max for each pixel (note that I had to change your exmple data because you were generating a stack with identical rasters):

r1 <- raster(nrows=10,ncols=100, vals =rnorm(1000))
r2 <- raster(nrows=10,ncols=100, vals =rnorm(1000))
r3 <- raster(nrows=10,ncols=100, vals =rnorm(1000))
r4 <- raster(nrows=10,ncols=100, vals =rnorm(1000))
r5 <- raster(nrows=10,ncols=100, vals =rnorm(1000))
s <- stack(r1,r2,r3,r4,r5) 
wheremax<-which.max(s)
plot(a)

to have the colors that you want, you just have to assign a proper color table when you plot wheremax

lbusett
  • 5,801
  • 2
  • 24
  • 47