Updated function definitions with argument defaults

R/center.R

@@ -5,13 +5,13 @@
 #' And even more
 #'
 #' @param dataset The numeric vector to be centered
-#' @param desired The numeric midpoint value around which the data will be centered
+#' @param desired The numeric midpoint value around which the data will be centered (default: 0)
 #'
 #' @return A new vector containing the original data centered around the desired values
 #'
 #' @examples
-#	center(c(1,2,3),0) # should return -1 0 1
+#	center(c(1,2,3)) # should return -1 0 1
 #	center(c(4,5,6),2) # should return 1 2 3
-center <- function(dataset, desired) {
-	dataset - mean(dataset) + desired
+center <- function(dataset, desired = 0) {
+    dataset - mean(dataset) + desired
 }

R/rescale.R

@@ -1,12 +1,14 @@
 #' Rescaling datasets
 #'
 #' @param v A numeric vector
+#' @param lower numeric (default:0)
+#' @param upper numeric (default:1)
 #'
-#' @return A new numeric vector, rescaled from the input vector to the range of 0 to 1
+#' @return A new numeric vector, rescaled from the input vector to a range defined by the `lower` and `upper` parameters (default: 0 and 1)
 #'
 #' @examples
-#'	rescale(c(1,2,3)) # [1] 0.0 0.5 1.0
-#'	rescale(c(1,2,3,4,5)) # [1] 0.00 0.25 0.50 0.75 1.00
-rescale <- function(v) {
-	(v - min(v)) / (max(v) - min(v))
+#'	rescale2(c(1,2,3)) # [1] 0.0 0.5 1.0
+#'	rescale2(c(1,2,3,4,5),1,2) # [1] 1.00 1.25 1.50 1.75 2.00
+rescale <- function(v, lower = 0, upper = 1) {
+	(v - min(v)) / (max(v) - min(v)) * (upper - lower) + lower
 }

tests/testthat/test-center.R

@@ -1,5 +1,6 @@
 context("test-center.R")
 
-test_that("centering works", {
-    expect_equal(center(c(1,2,3),0), c(-1,0,1))
+test_that("centering works, also relying on default of desired parameter", {
+    expect_equal(center(c(1,2,3)), c(-1,0,1))
+    expect_equal(center(c(1,2,3),1), c(0,1,2))
 })

tests/testthat/test-rescale.R

@@ -1,5 +1,9 @@
 context("test-rescale.R")
 
-test_that("rescaling works", {
+test_that("rescaling works, without overwriting the default", {
   expect_equal(rescale(1:5), 0.25*(0:4))
 })
+
+test_that("rescaling works, without nondefault arguments", {
+    expect_equal(rescale(1:3,1,2), c(1,1.5,2))
+})