How to index a multidimensional R array dynamically?

Question

I am working on some data in R that consist of four-dimensional arrays composed of three spatial dimensions and a time dimension: x, y, z, t. For some of my analyses, I woul

Answer 1

I think you are looking for:

apply(a4d, 4, `[`, indices)

And to check that our results match:

result1 <- matrix(result[,5], ncol = 10)
result2 <- apply(a4d, 4, `[`, indices)
identical(result1, result2)
# [1] TRUE