Local functions
Local functions for two RasterLayer objects (using a focal neighborhood)
## S4 method for signature 'RasterLayer,RasterLayer' localFun(x, y, ngb=5, fun, filename='', ...)
x |
RasterLayer or RasterStack/RasterBrick |
y |
object of the same class as |
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 |
RasterLayer
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
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)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.