Moving window regression

Question

I want to perform a moving window regression on every pixel of two raster stacks representing Band3 and Band4 of Landsat data. The result should be two additional stacks, on

Answer 1

Here is one approach, adapted from ?raster::localFun

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))

# local regression:
rfun <- function(x, y, ...) {
    d <- na.omit(data.frame(x, y))
    if (nrow(d) < 3) return(NA)
    m <- lm(y~x, data=d)
    # return slope
    coefficients(m)[2]
}

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

Unfortunately you will have to run this twice to get both the slope and intercept (coefficients(m)[1]).