distm_FUN for projections like UTM.

[SeltaZheng]

My rasters are in UTM projection and the distance is Euclidean. I used rater::pointDistance to calculate it.
I tried to use pointDistance for fitcor() but failed.
Any suggestions on distance functions that will work for UTM?

Thank you.

[morrowcj]

remotePARTS cannot handle rasters natively. you need to convert it into a flat format (e.g., a matrix).

Euclidean distances, or any other distances, can be used, with the "distm_FUN" argument, by simply passing a function that conforms to the following rules: 1) the first argument is a 2-column matrix of coordinates and 2) it returns a distance matrix. So for example the following function would work

euc_dist <- function(coords){
    as.matrix(stats::dist(coords))
}

And you could then pass it to fitCor either by reference:

fitCor(AR.map$residuals, coords, covar_FUN = "covar_exp", start = list(range = .1), distm_FUN = "euc_dist")

or inline:

fitCor(AR.map$residuals, coords, covar_FUN = "covar_exp", start = list(range = .1), distm_FUN = function(x){as.matrix(dist(x))})

[SeltaZheng]

Got it! Thanks for helping 👍

[morrowcj]

Of course, @SeltaZheng. Feel free to reach out for any else you need.