I have an equation to calculate `z` from multiplying several rasters and numbers as seen below: z <- a*b*c*d*e The raster layers and values are as below: set.seed(234) r <- rast(nrows=10, ncols=10) a <- setValues(r,runif(n = 100, min = 4, max=16)) b <- setValues(r,runif(n = 100, min = 0, max=100)) c <- setValues(r,runif(n = 100, min = 68, max=270)) d <- setValues(r,runif(n = 100, min = 0, max=1)) e <- setValues(r,runif(n = 100, min = 3, max=9)) I need to calculate uncertainty based on varying `c` and `e` by generating random rasters from within the minimum and maximum values. In the end, I need to plot an uncertainty map.