mkde (version 0.4)

computeSizeMKDE: Compute the area or volume of an MKDE.

Description

For 2D MKDEs, this function computes the area. For a 2.5D MKDE it computes the area based on the cell areas computed from an elevation raster. For a 3D MKDE, it computes the volume.

Usage

computeSizeMKDE(mkde.obj, prob)

Value

A vector with the areas or volumes is returned.

Arguments

mkde.obj

MKDE list object with density estimate calculated.

prob

Probabilities for the desired contours.

Author

Jeff A. Tracey, PhD
USGS Western Ecological Research Center, San Diego Field Station

James Sheppard, PhD
San Diego Zoo Institute for Conservation Research

Details

For a 2D or 2.5D MKDE list object, areas within the contours specified by quant are calculated. For a 3D MKDE, the volumes within the contours are calculated.

Examples

library(terra)
data(condor)

condor <- condor[1:20,] # simply to make example run more quickly
mv.dat <- initializeMovementData(condor$time, condor$x, condor$y, 
z.obs=condor$z, sig2obs=25.0, sig2obs.z=81.0, t.max=65.0)

fpath <- system.file("extdata", "condordem120.RDS", package="mkde")
condordem120 <- terra::readRDS(fpath)
cell.sz <- mean(res(condordem120))
ext <- ext(condordem120)
nx <- ncol(condordem120)
ny <- nrow(condordem120)
mkde.obj <- initializeMKDE3D(ext$xmin, cell.sz, nx, ext$ymin, cell.sz,
ny, min(values(condordem120), na.rm=TRUE), cell.sz, 25)

# note: we use a raster coarse integration time step so the
# example runs faster
dens.res <- initializeDensity(mkde.obj, mv.dat, integration.step=10.0)
mkde.obj <- dens.res$mkde.obj
mv.dat <- dens.res$move.dat

my.quantiles <- c(0.95, 0.75, 0.50)
res <- computeContourValues(mkde.obj, my.quantiles)
res$volume <- computeSizeMKDE(mkde.obj, my.quantiles)
print(res)