localFun function

Local functions

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

## 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

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

Returns

RasterLayer

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)