raster.vol {spatialEco}

Raster Percent Volume

Description

Calculates a percent volume on a raster or based on a systematic sample

Usage

raster.vol(
  x,
  p = 0.75,
  sample = FALSE,
  spct = 0.05,
  type = c("random", "regular")
)

Arguments

x

A terra SpatRaster class object

p

percent raster-value volume

sample

(FALSE/TRUE) base volume on systematic point sample

spct

sample percent, if sample (TRUE)

type

If sample=TRUE type of sample, options are "random" or "regular"

Value

if sample (FALSE) binary raster object with 1 representing designated percent volume else, if sample (TRUE) n sf POINT object with points that represent the percent volume of the sub-sample

Note

Since this model needs to operate on all of the raster values, it is not memory safe

Author(s)

Jeffrey S. Evans <[e-mail]>

Examples

library(terra)
  r <- rast(ncols=100, nrows=100)
    r[] <- runif(ncell(r), 0, 1)
    r <- focal(r, w=focalMat(r, 6, "Gauss"))
  #r[sample(1:ncell(r)),10] <- NA
  
  # full raster percent volume 
  p30 <- raster.vol(r, p=0.30)
  p50 <- raster.vol(r, p=0.50)
  p80 <- raster.vol(r, p=0.80)

opar <- par(no.readonly=TRUE)
    par(mfrow=c(2,2))
    plot(r, col=cm.colors(10), main="original raster")
    plot(p30, breaks=c(0,0.1,1), col=c("cyan","red"), legend=FALSE,
      main="30% volume")
    plot(p50, breaks=c(0,0.1,1), col=c("cyan","red"), legend=FALSE,
      main="50% volume")
    plot(p80, breaks=c(0,0.1,1), col=c("cyan","red"), legend=FALSE,
      main="80% volume")
par(opar)