Add cbind and rbind methods

Fixes #311

NAMESPACE

@@ -37,6 +37,7 @@ S3method(as_units,units)
 S3method(boxplot,units)
 S3method(c,mixed_units)
 S3method(c,units)
+S3method(cbind,units)
 S3method(diff,units)
 S3method(drop_units,data.frame)
 S3method(drop_units,mixed_units)
@@ -55,6 +56,7 @@ S3method(plot,units)
 S3method(print,mixed_units)
 S3method(print,units)
 S3method(quantile,units)
+S3method(rbind,units)
 S3method(rep,units)
 S3method(seq,units)
 S3method(set_units,logical)

NEWS.md

@@ -1,5 +1,7 @@
 # version devel
 
+* Add methods for `cbind` and `rbind`; fixes #311
+
 * Performance improvements in `data.frame` methods; suggested in #361 @grcatlin
 
 * Fix `weighted.mean.units` for unitless objects; #363

R/misc.R

@@ -136,3 +136,49 @@ unique.units <- function(x, incomparables = FALSE, ...) {
     NextMethod() else unique.array(x, incomparables, ...)
   .as.units(xx, units(x))
 }
+
+#' Combine R Objects by Rows or Columns
+#'
+#' S3 methods for \code{units} objects (see \code{\link[base]{cbind}}).
+#'
+#' @inheritParams base::cbind
+#' @name cbind.units
+#'
+#' @examples
+#' x <- set_units(1, m/s)
+#' y <- set_units(1:3, m/s)
+#' z <- set_units(8:10, m/s)
+#' (m <- cbind(x, y)) # the '1' (= shorter vector) is recycled
+#' (m <- cbind(m, z)[, c(1, 3, 2)]) # insert a column
+#' (m <- rbind(m, z)) # insert a row
+#' @export
+cbind.units <- function(..., deparse.level = 1) {
+  dots <- list(...)
+  stopifnot(all(sapply(dots, inherits, "units")))
+  u <- units(dots[[1]])
+  dots <- lapply(dots, function(x) {
+    d <- dim(x)
+    dn <- dimnames(x)
+    dots_unified <- set_units(x, u, mode = "standard")
+    ret <- as.numeric(dots_unified)
+    dim(ret) <- d
+    if (!is.null(dn)) dimnames(ret) <- dn
+    return(ret)
+  })
+
+  nm <- names(as.list(match.call()))
+  nm <- nm[nm != "" & nm != "deparse.level"]
+  if (is.null(nm))
+    names(dots) <- sapply(substitute(list(...))[-1], deparse)
+  else names(dots) <- nm
+
+  call <- as.character(match.call()[[1]])
+  value <- do.call(call, c(dots, deparse.level=deparse.level))
+  attr(value, "units") <- u
+  class(value) <- "units"
+  return(value)
+}
+
+#' @rdname cbind.units
+#' @export
+rbind.units <- cbind.units

tests/testthat/test_misc.R

@@ -157,3 +157,35 @@ test_that("duplicated-related methods work as expected", {
   expect_equal(anyDuplicated(x), anyDuplicated(drop_units(x)))
   expect_equal(unique(x), x[1, , drop=FALSE])
 })
+
+test_that("bind methods work properly", {
+  a <- set_units(1:10, m)
+  b <- set_units((1:10) * 0.001, km)
+
+  x <- rbind(x=a, y=a)
+  y <- rbind(x=a, y=b)
+  expect_equal(as.numeric(x), as.numeric(y))
+  expect_equal(rownames(x), c("x", "y"))
+  expect_equal(rownames(y), c("x", "y"))
+  x <- rbind(rbind(a, a), a)
+  y <- rbind(b, rbind(b, b))
+  expect_equal(as.numeric(x), as.numeric(y) * 1000)
+  expect_equal(rownames(x), c("a", "a", "a"))
+  expect_equal(rownames(y), c("b", "b", "b"))
+
+  x <- cbind(x=a, y=a)
+  y <- cbind(x=a, y=b)
+  expect_equal(as.numeric(x), as.numeric(y))
+  expect_equal(colnames(x), c("x", "y"))
+  expect_equal(colnames(y), c("x", "y"))
+  x <- cbind(cbind(a, a), a)
+  y <- cbind(b, cbind(b, b))
+  expect_equal(as.numeric(x), as.numeric(y) * 1000)
+  expect_equal(colnames(x), c("a", "a", "a"))
+  expect_equal(colnames(y), c("b", "b", "b"))
+
+  z <- cbind(
+    rbind(a, b),
+    rbind(x = a, y = b))
+  expect_equal(dimnames(z), list(c("a", "b"), NULL))
+})