--- a
+++ b/tests/testthat/test-unscale.R
@@ -0,0 +1,11 @@
+context("unscale")
+
+test_that("unscale works", {
+    
+    X <- matrix(1:9, ncol = 3)
+    X.scale <- scale(X, center = TRUE, scale = TRUE)
+    X.unscale <- unscale(X.scale)
+    
+    expect_is(X.unscale, "matrix")
+    expect_equal(X, X.unscale)
+})
\ No newline at end of file