Create Stratified Random Point Sample

library(terra)
library(sf)
library(dplyr)

fire <- rast("data/AnalysisReady/burn_severity_ba4.tif")
fire <- ifel(fire == 0 | fire == 9, NA, fire)

# Use spatSample to generate 20 random points per burn severity class
samp <- spatSample(fire, size = 20, method = "stratified", values = T, 
                   as.points = T)
# Convert to sf and rename the column
samp <- st_as_sf(samp)
samp <- rename(samp, burn_severity = Layer_1)

# save output
st_write(samp, "outputs/SpatialOutputs.gpkg", layer = "stratified_sample")