getEnvData: Provide pseudo-absent points and derive environmental...

In Xinhai-Li/abundanceR: Estimate wildlife abundance based on distance sampling and species distribution models

Provide pseudo-absent points and derive environmental variables

Description

This function provides pseudo-absent points using user defined sample size, derives values of environmental variables at occurrences and pseudo-absent points.

Usage

getEnvData(species, buffer, absence, Envlayers)

Arguments

species	A data.frame of species occurrences with columns "Name_E", "Lon", "Lat", "Date", "Count"
buffer	A value of distance (unit: degree) defining the width of buffer zone outside the occurrences
absence	The number of pseudo-absent points on the longitude side and the latitude side
Envlayers	A RasterBrick (a multi-layer raster object)

Value

Return a data.frame with values of environmental variables at occurrences and pseudo-absent points.

Author(s)

Xinhai Li ([e-mail])

Examples

 attach(species) # load occurrences data
 BioClim <- brick('D:/GIS/CLIMATE/var27.grd')
 Data = getEnvData(species, buffer=0.5, absence=30, Envlayers=BioClim); head(Data)

Xinhai-Li/abundanceR documentation built on Feb. 1, 2024, 4:47 a.m.