Fix #214

r-lib · Nov 2, 2023 · 60a4ca1 · 60a4ca1
1 parent 2e8d601
commit 60a4ca1
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diff --git a/NEWS.md b/NEWS.md
@@ -11,6 +11,8 @@
 * The `scale_cut` argument in `number()` now works as advertised for values 
   below the lowest cut value (#346)
 * `label_dollar()` has been superseeded by `label_currency()` for clarity (#344)
+* `sqrt_trans()` no longer returns an inverse for values outside of its domain 
+  (#214)
 
 # scales 1.2.1
 

diff --git a/R/trans-numeric.R b/R/trans-numeric.R
@@ -335,7 +335,7 @@ sqrt_trans <- function() {
   trans_new(
     "sqrt",
     "sqrt",
-    function(x) x^2,
+    function(x) ifelse(x < 0, NA_real_, x ^ 2),
     domain = c(0, Inf)
   )
 }
diff --git a/tests/testthat/test-trans.R b/tests/testthat/test-trans.R
@@ -27,3 +27,7 @@ test_that("trans has useful print method", {
     trans_new("test", transform = identity, inverse = identity)
   })
 })
+
+test_that("inverse of trans_sqrt() returns NA for values outside of range", {
+  expect_equal(sqrt_trans()$inverse(-2), NA_real_)
+})