build_testraster: build_testraster

In IREA-CNR-MI/sprawl: sprawl: Spatial Processing (in) R: Advanced Workflows Library

Description

helper function used to quickly create a rasterStack object with specified dimensions (useful for testing purposes).

Usage

build_testraster(nrows = 100, ncols = 100, nbands = 1,
  with_nodata = TRUE, to_file = FALSE, out_file = NULL, ...)

Arguments

nrows	numeric number of rows, Default: 100
ncols	numeric number of columns, Default: 100
nbands	numeric number of bands, Default: 1
with_nodata	PARAM_DESCRIPTION, Default: TRUE
to_file	logical if TRUE, the rasterStack is saved to a TIFF file, Default: FALSE
out_file	character filename where the test raster should be saved (ignored if to_file = NULL). If out_file is NULL, the file is saved in R temporary folder, otherwise the filename specified in out_file is used. In both cases, the name of the created TIFF file is returned instead than the rasterStack itself, Default: NULL.
...	Any other arguments to be passed to raster::raster while creating the output raster.

Value

Either the "test" raster in rasterStack format, or the filename where it was saved (if tofile = TRUE)

Note

• Values of the test raster are integers between 1 and 250.

• If out_file is selected, the file is saved as a 8-bit unsigned integer tiff to save space.

• By default, the raster is created using a WGS84 lat/lon reference system, with extent corresponding to the entire globe (bbox = -180, 180; -90, 90). To specify a different projection and extent, specify them by passing the crs and ext arguments to 'raster (see examples).

Examples

## Not run: 
 # create a rasterstack of 100*100 cells and 10 bands and put it in test_rast
 test_rast <- build_testraster(100,100,10)
 test_rast

 # create a rasterstack of 100*100 cells and 20 bands and save it to a temporary TIFF file
 test_rast <- build_testraster(100,100,20, to_file = TRUE)
 test_rast

 # create a rasterstack of 100*100 cells and 10 in epsg:3857 projection on a given extent
 build_testraster(100,100,10, crs = "+init=epsg:3857",
                              ext = raster::extent(c(0, 200000, 0, 200000)))
 test_rast

## End(Not run)

IREA-CNR-MI/sprawl documentation built on May 27, 2019, 1:12 p.m.