getID: Derive 1 degree cell IDs

In GSIF: Global Soil Information Facilities

Description

Derives ID's of the 1 degree cells in the default land mask for a given polygon defining the spatial domain of interest.

Usage

## S4 method for signature 'SpatialPolygons'
getID(obj, pixsize = 3/3600, empty.tif = FALSE, 
      compress = FALSE, zipname = set.file.extension(tempfile(tmpdir = getwd()), "zip"))

Arguments

obj	object of class "SpatialPolygons"; must be in geographical coordinates (WGS84)
pixsize	grid cell size in decimal degrees (set at 0.0008333333 or 100 m around equator)
empty.tif	logical; specify whether a GeoTiff mask file should be created
compress	logical; specify whether to compress GeoTiffs
zipname	(optional); zip archive file name

Value

The output is a vector of grid cell ID names e.g. W79_N83. These can be further used to automate digital soil mapping for large areas.

Note

This operation can be time consuming for large areas (e.g. continents).

Author(s)

Tomislav Hengl

See Also

landmask

Examples

library(sp)
## Bounding box for Malawi:
bbox = expand.grid(lon=c(32.67152, 35.915046), lat=c(-17.12721, -9.363796))
bbox[5,] <- bbox[1,]
crs = CRS("+proj=longlat +datum=WGS84")
x <- SpatialPolygons(list(Polygons(list(Polygon(bbox)), ID="1")), proj4string=crs)
ID.lst <- getID(x)

GSIF documentation built on May 2, 2019, 5:44 p.m.