I am trying to randomly distribute points in a raster (that has 11 unique values). I followed this posting and was able to recreate it, being partially successful.
As mentioned about, my raster has 11 unique values and I want different number of points randomly placed based on the unique strata. Also, I need different number of points.
So as the posting says,I isolated individual unique layers based on the unique value
raster[raster != 81] = NA # creating a raster with pixels of value 82 and remaining pixels Nodata
Then I used the sampleStratified() function as mentioned int he post
x<-sampleStratified(raster,1 , sp=T)
I want only 1 point to be randomly placed and I get this error
Error: size > 0 is not TRUE In addition: Warning messages: 1: In .local(x, size, ...) : fewer samples than requested found for stratum: 81
I don't understand how to rectify this because there are over 2000 pixels in the raster with pixels of value 81. So does this mean that sampleStratified() was not able to place 1 point in any of the >2000 pixels present? How do I rectify this error.