R: Local functions

localFun {raster} | R Documentation

## 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)

[Package raster version 2.6-7 Index]