Added support for 3D arrays

R/repmat.R

@@ -3,15 +3,16 @@
 #' @details This function was created to replicate the behavior of a homonymous
 #' function on Matlab
 #' @param mx matrix
-#' @param n either a scalar with the number of replications in both rows and columns or a 2-length vector with individual repetitions.
+#' @param n either a scalar with the number of replications in both rows and
+#' columns or a <= 3-length vector with individual repetitions.
 #' @return matrix replicated over `ncol(mx) * n` columns and `nrow(mx) * n` rows
 #' @note The Matlab implementation of this function accepts `n` with length > 2.
-#' 
+#'
 #' It should also be noted that a concatenated vector in R, e.g. `c(5, 2)`, becomes a column vector when coerced to matrix, even though it may look like a row vector at first glance. This is important to keep in mind when considering the expected output of this function. Vectors in R make sense to be seen as column vectors, given R's Statistics-oriented paradigm where variables are usually disposed as columns in a dataset.
 #' @export
 repmat <- function (mx, n) {
     # Validation
-    if (length(n) > 2) warning("Extra dimensions of n ignored")
+    if (length(n) > 3) warning("Extra dimensions of n ignored")
     if (length(n) == 1) n <- rep(n, 2)
     if (class(mx) != "matrix") mx <- as.matrix(mx)
 
@@ -23,6 +24,9 @@ repmat <- function (mx, n) {
         for (i in seq(n[1] - 1)) out <- rbind(out, mx_col)
     }
 
+    # Replicating 3rd dimension
+    if (!is.na(n[3]) & n[3] > 1) out <- array(out, c(dim(out), n[3]))
+
     # Output
-    return(unname(as.matrix(out)))
+    return(unname(as.array(out)))
 }

tests/testthat/test-convertedBaseFunctions.R

@@ -28,6 +28,10 @@ test_that("repmat works properly", {
         object = repmat(mx2, c(4, 1)),
         expected = rbind(mx2, mx2, mx2, mx2)
     )
+    expect_equal(
+        object = repmat(mx2, c(1, 1, 2)),
+        expected = array(mx2, c(2, 2, 2))
+    )
 })
 
 test_that("zeros and ones work as expected", {