Agustin Lobo <Agustin.Lobo at ija.csic.es> writes:
ai <- as.im(a) ai$v[ai$v==0]<-NA #0 values in the raster are the background adist <- distmap(as.owin(ai)) adistlog <- adist adistlog$v <- log(adistlog$v+1) #log transform
In spatstat you can also use 'solutionset' to find the pixels that satisfy a logical statement, and `eval.im' to do calculations with pixel values. The code above is equivalent to ai <- as.im(a) aw <- solutionset(ai != 0) adist <- distmap(aw) adistlog <- eval.im(log(adist)+1) Adrian Baddeley