background.buffer {ENMTools}

Takes a set of points, a buffer radius, a buffer type, and a mask and returns either a raster, a polygon, or background points representing the species background. Code modified from Elith and Hijmans SDM with R tutorial

Description

Takes a set of points, a buffer radius, a buffer type, and a mask and returns either a raster, a polygon, or background points representing the species background. Code modified from Elith and Hijmans SDM with R tutorial

Usage

background.buffer(
  points,
  buffer.width,
  buffer.type = "circles",
  mask = NA,
  return.type = "raster",
  n = 1000
)

Arguments

points

A two column data frame with X and Y coordinates

buffer.width

Radius for circular buffers to draw around points, for buffer.type = circular. If buffer.type = "convhull", denotes the amount to which the initial polygon should be buffered. It's worth noting that this argument may in some cases be treated as map units (e.g., lat and long), but in other caess may be treated as meters. If you're getting weird behavior, you might try changing the units you're using to specify buffer.width.

buffer.type

Which method to use for buffering species occurrence points. Currently accepts "circles" and "convhull".

mask

A raster to use as a mask for trimming the buffer if the return type is "raster" or "points"

return.type

What type of object to return. Can be "raster", "polygon", or "points".

n

Sample size for number of background points to return, for return.type = "points".

Value

Either a raster, a polygon, or a data frame of points representing the species background.