I want to use a raster to stratify an image using different texture. I have a raster image (ndvi_2019) for which I want to extract random coordinates as points from each classes. First, I want to form these create these classes I want to extract these coordinates by classing the values in the ndvi raster object as below;
class 1= <0 class 2= 0:0.1 class 3= 0.1:0.2 class 4 = >0.2
The assumption is that the classification forms the different strata which can then indicate different strata.
ndvi_2019<- (choma_clip[]- choma_clip[])/(choma_clip[]+choma_clip[]) r<- ndvi_2019
r<- setValues(r, rnorm(ncell(r))) pts<- spsample(as(extent(r@extent, "SpatialPolygons"), 30, type="random")) class1<- r/r <0 class2<- r/r[r== 0:0.1]] class3<- r/r[[r== 0.1:0.2]] class4 <- r/r>0.2