Write raster data to a file
Write a SpatRaster object to a file.
## S4 method for signature 'SpatRaster,character' writeRaster(x, filename, overwrite=FALSE, ...)
x |
SpatRaster |
filename |
character. Output filename |
overwrite |
logical. If |
... |
additional arguments for for writing files. See Details |
In writeRaster, and in other methods that generate SpatRaster objects, options for writing raster files to disk can be provided as additional arguments or, in a few cases, as the wopt argument (a named list) if the additional arguments are already used for a different purpose. The following options are available:
| name | description |
datatype
|
values for datatype are "INT1U", "INT2U", "INT2S", "INT4U", "INT4S", "FLT4S", "FLT8S". The first three letters indicate whether the datatype is integer (whole numbers) of a real number (decimal numbers), the fourth character indicates the number of bytes used (allowing for large numbers and/or more precision), and the "S" or "U" indicate whether the values are signed (both negative and positive) or unsigned (positive values only). |
filetype
|
file format expresses as GDAL driver names. If this argument is not supplied, the driver is derived from the filename. |
gdal
|
GDAL driver specific datasource creation options. See the GDAL documentation. For example, with the GeoTiff file format you can use gdal=c("COMPRESS=DEFLATE", "TFW=YES"). |
tempdir
|
the path where temporary files are to be written to. |
progress
|
positive integer. If the number of chunks is larger, a progress bar is shown. |
memfrac
|
numeric between 0.1 and 0.9. The fraction of available RAM that terra is allowed to use. |
names
|
output layer names. |
NAflag
|
numeric. value to represent missing (NA or NaN) values. See note |
verbose
|
logical. If TRUE debugging information is printed. |
todisk
|
logical. If TRUE processing operates as if the dataset is very large and needs to be written to a temporary file (for debugging). |
SpatRaster. This function is used for the side-effect of writing values to a file.
GeoTiff files are, by default, written with LZW compression. If you do not want compression, use gdal="COMPRESS=NONE".
When writing integer values the lowest available value (given the datatype) is used for signed types, and the highest value is used for unsigned values. This can be a problem with byte data (between 0 and 255) as the value 255 is reserved for NA. To keep the value 255, you need to set another value as NAflag, or do not set a NAflag (with NAflag=NA)
see writeCDF for writing NetCDF files.
library(terra)
r <- rast(nrow=5, ncol=5, vals=1:25)
# create a temporary filename for the example
f <- file.path(tempdir(), "test.tif")
writeRaster(r, f, overwrite=TRUE)
writeRaster(r, f, overwrite=TRUE, gdal=c("COMPRESS=LZW", "TFW=YES","of=COG"), datatype='INT1U')
## Or with a wopt argument:
writeRaster(r, f, overwrite=TRUE, wopt= list(gdal=c("COMPRESS=LZW", "of=COG"), datatype='INT1U'))
## remove the file
unlink(f)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.