Hi!
Given a brick object (longitude, latitude, time), I need a (lon,lat)
layer with the maximum value of each cell across time.
That's the equivalent to
> x = array(round(runif(n=3*4*5,min=0,max=10)),dim=c(3,4,5))
> apply(x,c(1,2),max,na.rm=T)
but for x being a brick object. How can I do it with raster?
I've tried
> funmax <- function(x) {apply(x,c(1,2),max,na.rm=T)}
> show(br)
class : RasterBrick
filename :
nlayers : 3
nrow : 5
ncol : 5
ncell : 25
projection : NA
min value : ? ? ?
max value : ? ? ?
extent : 0, 1, 0, 1 (xmin, xmax, ymin, ymax)
resolution : 0.2, 0.2 (x, y)
> brmax <- calc(br,funmax)
But the result is wrong, as it should be 1 layer and not 3:
> show(brmax)
class : RasterBrick
filename :
nlayers : 3
nrow : 5
ncol : 5
ncell : 25
projection : NA
min value : 232 232 248
max value : 248 248 248
extent : 0, 1, 0, 1 (xmin, xmax, ymin, ymax)
resolution : 0.2, 0.2 (x, y)
I've also tried with stackApply(), but do not think that's the way to go.
Also, I'm concerned that apply() is typically very slow in R, and I'm
dealing with a large brick object.
Thanks
Agus
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