computeSizeMKDE: Compute the area or volume of an MKDE.

In mkde: 2D and 3D Movement-Based Kernel Density Estimates (MKDEs)

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)	

Arguments

mkde.obj	MKDE list object with density estimate calculated.
prob	Probabilities for the desired contours.

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.

Value

A vector with the areas or volumes is returned.

Author(s)

Jeff A. Tracey, PhD
USGS Western Ecological Research Center, San Diego Field Station
[e-mail]
James Sheppard, PhD
San Diego Zoo Institute for Conservation Research
[e-mail]

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)

mkde documentation built on April 3, 2025, 11:44 p.m.