library(doParallel) registerDoParallel() # Define a function that creates an iterator that returns subvectors ivector <- function(x, chunks) { n <- length(x) i <- 1 nextEl <- function() { if (chunks <= 0 || n <= 0) stop('StopIteration') m <- ceiling(n / chunks) r <- seq(i, length=m) i <<- i + m n <<- n - m chunks <<- chunks - 1 x[r] } obj <- list(nextElem=nextEl) class(obj) <- c('abstractiter', 'iter') obj } # Define the coordinate grid and figure out how to split up the work x <- seq(-10, 10, by=0.1) nw <- getDoParWorkers() cat(sprintf('Running with %d worker(s)\n', nw)) # Compute the value of the sinc function at each point in the grid z <- foreach(y=ivector(x, nw), .combine=cbind) %dopar% { y <- rep(y, each=length(x)) r <- sqrt(x ^ 2 + y ^ 2) matrix(10 * sin(r) / r, length(x)) } # Plot the results as a perspective plot persp(x, x, z, ylab='y', theta=30, phi=30, expand=0.5, col="lightblue")