Error in overlay - formula not vectorized

I’ve run into another error while trying to get my predictive model to work. My base model is basically done (extracting locational parameters from archaeological sites in an area, and calculating a predictive map for archaeological risk areas, containing slope, tpi, tpi_15, aspect and distance to water), but it is not as accurate as I’d like it to be. So I’m trying to assign different weights to the parameters (e.g. distance to water is more important than aspect), and that’s where I’m stuck.

weights <- apply(X = sn_sf_bind, MARGIN = 2, FUN = function(x)
{sqrt(1/sd(x)*range(x)[2]-range(x)[1])})

sn_sf_bind is my table with the archaeological sites and assigned locational parameters, looks like this:

For this I don’t get an error, but I don’t know if it could be in there already.

The code that isn’t working is this:

wba <- overlay(x = ter_par_big,
               fun=function(w,x,y,z){
                 return((v*weights[1])+
                          (w*weights[2])+
                          (x*weights[3])+
                          (y*weights[4])+
                          (z*weights[5]))},
               unstack = TRUE)

I’ve also tried this:

fw <- function(v,w,x,y,z){
  return((v*weights[1])+
           (w*weights[2])+
           (x*weights[3])+
           (y*weights[4])+
           (z*weights[5]))}

wba <- overlay(x = ter_par_big,
               fun=Vectorize(fw),
               unstack = TRUE)

But it didn’t change anything, I’m still getting the same error:

Error in .overlayList(x, fun = fun, filename = filename, forcefun = forcefun,  : 
  cannot use this formula, probably because it is not vectorized

ter_par_big is my Raster Brick, consisting of 5 layers with the locational parameters for the overall area, it looks like this: