ecospat (version 3.3)

ecospat.sample.envar: Sample Environmental Variables

Description

Add environmental values to a species dataframe.

Usage

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

Value

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

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.

Author

Olivier Broennimann

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.

Examples

# \donttest{
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))
# }