localFun: Local functions

In raster: Geographic Data Analysis and Modeling

Local functions

Description

Local functions for two RasterLayer objects (using a focal neighborhood)

Usage

## S4 method for signature 'RasterLayer,RasterLayer'
localFun(x, y, ngb=5, fun, filename='', ...)

Arguments

x	RasterLayer or RasterStack/RasterBrick
y	object of the same class as x, and with the same number of layers
ngb	integer. rectangular neighbourhood size. Either a single integer or a vector of two integers c(rows, cols), such as c(3,3) to have a 3 x 3 focal window
fun	function
filename	character. Output filename (optional)
...	additional arguments as for writeRaster

Value

RasterLayer

Note

The first two arguments that fun needs to accept are vectors representing the local cells of RasterLayer x and y (each of length ngb * ngb). It also must have an ellipsis (...) argument

See Also

corLocal, localFun

Examples

set.seed(0)
b <- stack(system.file("external/rlogo.grd", package="raster"))
x <- flip(b[[2]], 'y') + runif(ncell(b))
y <- b[[1]] + runif(ncell(b))

f <- localFun(x, y, fun=cor)

## Not run: 
# local regression:
rfun <- function(x, y, ...) {
	m <- lm(y~x)
	# return R^2
	summary(m)$r.squared
}

ff <- localFun(x, y, fun=rfun)
plot(f, ff)

## End(Not run)

raster documentation built on Oct. 3, 2024, 1:08 a.m.