A land mask based on the full ETOPO1 dataset
etopoMask( basename = "ETOPO1_Bed_c_geotiff", path = ".", tmp = path, land = FALSE )
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. |
a logical indicating whether the point is land or sea.
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.