ecospat (version 3.4)

ecospat.recstrat_regl: Random Ecologically Stratified Sampling of equal numbers

Description

This function randomly takes an equal number of samples per class in the stratification layer.

Usage

ecospat.recstrat_regl(in_grid, sample_no)

Value

Returns a dataframe with the selected sampling locations their coordinates and the strata they belong in.

Arguments

in_grid

The stratification grid to be sampled.

sample_no

The total number of pixels to be sampled.

Author

Achilleas Psomas and Niklaus E. Zimmermann

Details

The number of classes in the stratification layer is determined automatically from the integer input map. If the number of pixels in a class is higher than the number of samples, then a random selection without re-substitution is performed, otherwise all pixels of that class are selected.

See Also

ecospat.recstrat_prop ecospat.rcls.grd

Examples

  library(raster)
  library(classInt)

  bio3<- raster(system.file("external/bioclim/current/bio3.grd",package="biomod2"))
  bio12<- raster(system.file("external/bioclim/current/bio12.grd",package="biomod2"))
    
  B3.rcl<-ecospat.rcls.grd(bio3,9) 
  B12.rcl<-ecospat.rcls.grd(bio12,9)
  B3B12.comb <- B12.rcl+B3.rcl*10
    
  B3B12.regl_samples <- ecospat.recstrat_prop(B3B12.comb,100)
  
  plot(B3B12.comb)
  points(B3B12.regl_samples$x,B3B12.regl_samples$y,pch=16,cex=0.6,col=B3B12.regl_samples$class)