ecospat.sample.envar: Sample Environmental Variables

In ecospat: Spatial Ecology Miscellaneous Methods

Sample Environmental Variables

Description

Add environmental values to a species dataframe.

Usage

ecospat.sample.envar (dfsp, colspxy, colspkept = "xy", dfvar, 
colvarxy, colvar = "all", resolution)

Arguments

dfsp	A species dataframe with x (long), y (lat) and optional other variables.
colspxy	The range of columns for x (long) and y (lat) in dfsp.
colspkept	The columns of dfsp that should be kept in the final dataframe (default: xy).
dfvar	A dataframe object with x, y and environmental variables.
colvarxy	The range of columns for x and y in dfvar.
colvar	The range of enviromental variable columns in dfvar (default: all except xy).
resolution	The distance between x,y of species and environmental datafreme beyond which values shouldn't be added.

Details

The xy (lat/long) coordinates of the species occurrences are compared to those of the environment dataframe and the value of the closest pixel is added to the species dataframe. When the closest environment pixel is more distant than the given resolution, NA is added instead of the value. This function is similar to sample() in ArcGIS.

Value

A Dataframe with the same rows as dfsp, with environmental values from dfvar in column.

Author(s)

Olivier Broennimann [e-mail]

Examples

data("ecospat.testNiche")
spp <- ecospat.testNiche
sp1 <- spp[1:32,2:3]
names(sp1)<-c("x","y")
occ.sp1 <- ecospat.occ.desaggregation(xy=sp1,min.dist=500)
clim <- ecospat.testData[2:8]

occ_sp1 <- na.exclude(ecospat.sample.envar(dfsp=occ.sp1,colspxy=1:2,colspkept=1:2,
                                            dfvar=clim,colvarxy=1:2,colvar="all",resolution=25))

ecospat documentation built on July 4, 2024, 5:06 p.m.