raster (version 3.5-21)

blockSize: Block size for writing files

Description

This function can be used to suggest chunk sizes (always a number of entire rows), and corresponding row numbers, to be used when processing Raster* objects in chunks. Normally used together with writeValues.

Usage

blockSize(x, chunksize, n=nlayers(x), minblocks=4, minrows=1)

Value

A list with three elements:

rows, the suggested row numbers at which to start the blocks for reading and writing,

nrows, the number of rows in each block, and,

n, the total number of blocks

Arguments

x

Raster* object

chunksize

Integer, normally missing. Can be used to set the block size; unit is number of cells. Block size is then computed in units of number of rows (always >= 1)

n

Integer. number of layers to consider. The function divides chunksize by n to determine blocksize

minblocks

Integer. Minimum number of blocks

minrows

Integer. Minimum number of rows in each block

See Also

writeValues

Examples

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