writeRaster: Write raster data to a file

Description

Write an entire Raster* object to a file, using one of the many supported formats. See writeValues for writing in chunks (e.g. by row). When writing a file to disk, the file format is determined by the 'format=' argument if supplied, or else by the file extension (if the extension is known). If other cases the default format is used. The 'factory-fresh' default format is 'raster', but this can be changed using setOptions.

Usage

writeRaster(x, filename, ...)

Arguments

Raster* object

filename

Output filename

...

Additional arguments. See below, under Methods

Value

This function is used for the side-effect of writing values to a file.

Methods

Full function call when x is a RasterLayer object writeRaster(x, filename='', ...) rll{ x RasterLayer object filename Output filename ... Additional arguments. See below } Full function call when x is a RasterBrick or RasterStack object writeRaster(x, filename='', bandorder='BIL', ...) rll{ x RasterLayer object filename Output filename bandorder Character. 'BIL', 'BIP', or 'BSQ'. For 'native' file formats only. For some other formats you can use the 'options' arugment (see below) .. Additional arguments. See below } Additional arguments rll{ options Character. File format specific GDAL options. E.g., when writing a geotiff file: options=c("COMPRESS=NONE", "TFW=YES") format Character. Output file type. See writeFormats datatype Character. Output data type. See dataType overwrite Logical. If TRUE, "filename" will be overwritten if it exists NAflag Numeric. To overwrite the default value used to represent NA in a file } NetCDF files have the following additional, optional, arguments: varname, varunit, longname, xname, yname, zname, zunit.

Details

See writeFormats for supported file types ("formats", "drivers"). The rgdal package is needed, except for these file formats: 'raster', 'BIL', 'BIP', 'BSQ', 'SAGA', 'ascii', 'IDRISI', and 'CDF'. Some of these formats can be used with or without rgdal (idrisi, SAGA, ascii). You need the 'ncdf' library for the 'CDF' format. In multi-band files (i.e. files saved from RasterStack or RasterBrick objects), in the native 'raster' format, the bandorder can be set to BIL ('Bands Interleaved by Line'), BIP ('Bands Interleaved by Pixels') or BSQ ('Bands SeQuential'). Note that bandorder is not the same as filetype here. Supported file types include: llllr{ File type Long name default extension Multiband support raster 'Native' raster package format .grd Yes ascii ESRI Ascii .asc No SAGA SAGA GIS .sdat No IDRISI IDRISI .rst No CDF netCDF (requires ncdf) .nc Yes GTiff GeoTiff (requires rgdal) .tif Yes ENVI ENVI .hdr Labelled .envi Yes EHdr ESRI .hdr Labelled .bil Yes HFA Erdas Imagine Images (.img) .img Yes }

Examples

Run this code

r <- raster(system.file("external/test.grd", package="raster"))

# take a small part
r <- crop(r, extent(179880, 180800, 329880, 330840) )

# write to an integer binary file
rf <- writeRaster(r, filename="allint.grd", datatype='INT4S', overwrite=TRUE)

# make a brick and save multi-band file
b <- brick(r, sqrt(r))
bf <- writeRaster(b, filename="mutli.grd", bandorder='BIL', overwrite=TRUE)

# write to a new geotiff file (depends on rgdal)
if (require(rgdal)) {
  rf <- writeRaster(r, filename="test.tif", format="GTiff", overwrite=TRUE)
  bf <- writeRaster(b, filename="mutli.tif", options="INTERLEAVE=BAND", overwrite=TRUE)
}
 
# write to netcdf 
if (require(ncdf)) {	
 rnc <- writeRaster(r, filename='netCDF.nc', format="CDF", overwrite=TRUE)   
}

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