Land Mask

A land mask based on the full ETOPO1 dataset

Usage

etopoMask(
  basename = "ETOPO1_Bed_c_geotiff",
  path = ".",
  tmp = path,
  land = FALSE
)

Arguments

basename

the name of the etopo geotiff (without file extension).

path

the path to a folder containing the etopo geotiff

tmp

the path to a writeable folder

land

the logical value to return for land.

Value

a logical indicating whether the point is land or sea.

Details

Generate a land mask function based on ETOPO1 topography. The etopo geotiff is not bundled with the package and must be downloaded from https://www.ngdc.noaa.gov/mgg/global/global.html.

When the mask is intially created, a native raster (grd, gri) version of the geotiff is created in the directory tmp, which must be writable. This file can be deleted when the computation is finished.

The land argument determines whether the mask function returns TRUE or FALSE for land. The mask is constant and the tm argument to the mask is ignored.