Write a raster window

The mirror of read_raster(), with the same window and the same output size, so values read at one size can be written back at another and GDAL resamples between them.

Usage

write_raster(
  x,
  values,
  window = NULL,
  out_size = NULL,
  resample = "nearest",
  bands = NULL
)

Arguments

x

A GDALRasterBand, or a GDALDataset.

values

For a band, a numeric vector. For a dataset, a list of one numeric vector per band in bands.

window

Numeric of length 4: c(xoff, yoff, xsize, ysize) in pixels. Defaults to the whole raster.

out_size

Integer of length 2: the width and height of the block of values being given. Defaults to the size of the window, which is a write with no resampling.

resample

How to resample when out_size differs from the window. One of "nearest", "bilinear", "cubic", "cubicspline", "lanczos", "average", "mode", "gauss", "rms".

bands

For a dataset, which bands to write, one-based. Defaults to all of them. Writing several at once is one pass over the data.

Value

x, invisibly.

Details

Values go in the order they come out: the first row first, x varying fastest, which is the transpose of what matrix() builds from a vector.

Whatever the band holds, values are given as doubles and GDAL converts. A value the band's type cannot hold is clamped by GDAL rather than wrapped, and it says so.

The dataset has to be open for writing: one from gdal_create(), or one opened with gdal_open(path, update = TRUE). Nothing is guaranteed to be on disk until the dataset is closed with gdal_close(), or gdal_flush() is called.

Examples

path <- tempfile(fileext = ".tif")
ds <- gdal_create(path, 4, 4, bands = 1, type = "Byte")

write_raster(ds, list(as.double(seq_len(16))))
read_raster(ds)[[1]]
#>  [1]  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16

gdal_close(ds)
unlink(path)