ecospat (version 3.3)

ecospat.recstrat_prop: Random Ecologically Stratified Sampling of propotional numbers

Description

This function randomly collects a user-defined total number of samples from the stratification layer.

Usage

ecospat.recstrat_prop(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 samples per class are determined proportional to the abundance of each class. The number of classes in the stratification layer are determined automatically from the integer input map. If the proportion of samples for a certain class is below one then no samples are collected for this class.

See Also

ecospat.recstrat_regl 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.prop_samples <- ecospat.recstrat_prop(B3B12.comb,100)
    
    plot(B3B12.comb)
    points(B3B12.prop_samples$x,B3B12.prop_samples$y,pch=16,cex=0.6,col=B3B12.prop_samples$class)