Assuming I would have a raster in R like :
r <- raster(ncols=10, nrows=10)
r[] <- sample(50, 100, replace=T)
How could I set the values between [10,30] for example to NA?
I tried values = r[r<= c(10,30)] = NA but this does not remove the values between 10 and 30.
Thanks in advance.
Using
r[r <= 10:30] <- NA
seems dangerous, and in fact it gives a warning:
Warning message: In getValues(e1) <= e2 : longer object length is not a multiple of shorter object length
It is also not memory-friendly for large rasters.
The proper/best way to do this is to use raster::reclassify:
r <- raster::reclassify(r, c(10, 30, NA))
, which is also much faster.
See also:
You have to find the values like this:
r[r>10 & r<30]<-NA
r[]
[1] NA 38 NA 1 NA NA 3 32 40 36 NA NA 30 5 2 38 47 NA 42 42 1 NA NA 32 43 NA 7 NA 8 35 NA NA NA 48 10
[36] 32 49 33 NA 48 NA 37 2 45 9 7 37 42 2 42 NA 3 49 48 NA NA 48 5 NA 46 43 NA NA NA 42 39 41 NA 48 NA
[71] NA NA 30 35 32 46 4 32 NA 48 40 2 44 45 NA NA NA 9 47 NA NA 41 2 4 42 30 NA 36 48 32
