How to create 10 random rasters in R?

问题

I am looking to generate several random raster in a loop that I plan to store. I tried something (below) that but it does not work:

r1= raster(nrows = 1, ncols = 1, res = 0.5, xmn = -1.5, xmx = 1.5, ymn = -1.5, ymx = 1.5, vals = 0.3)

a<- 10
for (i in 1:length(a)){
values(r1[i]) = round(runif(ncell(r1[i]), 0, 1))}

Thanks for any help.

回答1:

There's a much simpler way:

library(raster)

r1 <- raster(nrows = 1, ncols = 1, res = 0.5, xmn = -1.5, xmx = 1.5, ymn = -1.5, ymx = 1.5, vals = 0.3)

rr <- lapply(1:10, function(i) setValues(r1,runif(ncell(r1))))

This gives you a list rr with 10 random rasters.

Using lapply is optionally, you could also use a verbose loop. But like this the rasters are stored directly in a tidy list.

回答2:

runif() is a good approach to generate random values. the matrix() function is a way to create a raster. I stock the raster values in a list object.

n <- 10
x_length <- 5
y_length <- 5

raster <- list(NULL)
for (i in 1:n){
    raster[[i]] <- round(
      matrix(
        runif(x_length * y_length , 1, 10), 
        x_length, y_length)
      )
}
raster

来源：https://stackoverflow.com/questions/52658006/how-to-create-10-random-rasters-in-r