Raster Percent Volume
Calculates a percent volume on a raster or based on a systematic sample
raster.vol(x, p = 0.95, sample = FALSE, spct = 0.05)
x |
raster class object |
p |
percent raster-value volume |
sample |
base volume on systematic point sample (TRUE/FALSE) |
spct |
sample percent, if sample (TRUE) |
if sample (FALSE) binary raster object with 1 representing designated percent volume else, if sample (TRUE) n sp SpatialPointsDataFrame object with points that represent the percent volume of the sub-sample
Since this model needs to operate on all of the raster values, it is not memory safe
Jeffrey S. Evans <jeffrey_evans@tnc.org>
require(raster)
r <- raster(ncols=100, nrows=100)
r[] <- runif(ncell(r), 0, 1)
r <- focal(r, w=focalWeight(r, 6, "Gauss"))
r[sample(1000, 1:ncell(r))] <- 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)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.