set_projarea: Select area for projection based on the extent of occ points

In HemingNM/ENMwizard: Advanced Techniques for Ecological Niche Modeling Made Easy

Select area for projection based on the extent of occ points

Description

This function will create SpatialPolygons that will be used to crop/mask raster/brick objects to be used on model projections. It has several options The user can crop a squared area with an extent larger than the extent of occ.poly. By default, the "extent increase" is the maximum of latitudinal and longitudinal extent "max(abs(ext.proj[1]-ext.proj[2]), abs(ext.proj[3]-ext.proj[4]))". The result is added to each side of the occ.poly extent. This may be changed by setting "mult", which will be multiplied by the "extent increase". Latitudinal and longitudinal increase may also vary independently by setting "same=FALSE".

Usage

set_projarea(
  occ.poly,
  sp.nm = "sp",
  deg.incr = NULL,
  mult = 1,
  buffer = FALSE,
  same = TRUE
)

Arguments

occ.poly	list of species SpatialPolygons
sp.nm	name (of species) to give to saved object
deg.incr	used to manually set the increase in prediction area, relative to occ.poly
mult	how much increase or decrease buffer
buffer	should the area be cut using a buffer around occ.poly?
same	should latitudinal and longitudinal increase vary independently?

Details

The user can also set a buffer around occ.poly to cut the raster/brick object. Buffer value is, by default, calculated in the same way as "extent increase", using "max(abs(ext.proj[1]-ext.proj[2]), abs(ext.proj[3]-ext.proj[4]))". But the exact value can be defined through "deg.incr" and "mult". This method takes longer to run.

Value

SpatialPolygons (enlarged occ.poly)

See Also

set_projarea_b

HemingNM/ENMwizard documentation built on Jan. 4, 2024, 3:24 p.m.