apply_windowed: Apply a raster function with edge effects over a series of...

In azvoleff/teamlucc: TEAM land use and cover change data processing toolkit

Description

This function can be useful when applying windowed functions over a raster, as with glcm. This function allows windowed functions that have edge effects to be applied over a raster in block-by-block fashion. apply_windowed avoids the striping that would result if the edge effects were ignored.

Usage

apply_windowed(x, fun, edge = c(0, 0), chunksize = NULL, filename = "",
  overwrite = FALSE, datatype = "FLT4S", ...)

Arguments

x	a Raster*
fun	the function to apply
edge	length 2 numeric with number of rows on top and bottom with edge effects, defined as c(top, bottom)
chunksize	the number of rows to read per block (passed to raster blockSize function.
filename	file on disk to save Raster* to (optional)
overwrite	whether to overwrite any existing files (otherwise an error will be raised)
datatype	the raster datatype to use
...	additional arguments to pass to fun

Examples

## Not run: 
L5TSR_1986_b1 <- raster(L5TSR_1986, layer=1)
min_x <- cellStats(L5TSR_1986_b1, 'min')
max_x <- cellStats(L5TSR_1986_b1, 'max')
apply_windowed(L5TSR_1986_b1, glcm, edge=c(1, 3), min_x=min_x, max_x=max_x)

## End(Not run)

azvoleff/teamlucc documentation built on May 11, 2019, 5:19 p.m.