math/cmplx: specify which square root Sqrt returns

Fixes #7851. LGTM=bradfitz R=golang-codereviews, bradfitz CC=golang-codereviews https://golang.org/cl/93200043
2014-05-09 16:04:03 -04:00 · 2014-05-09 16:04:03 -04:00 · 2182d5786b
parent e5c105033a
commit 2182d5786b
1 changed files with 1 additions and 0 deletions
--- a/src/pkg/math/cmplx/sqrt.go
+++ b/src/pkg/math/cmplx/sqrt.go
@ -54,6 +54,7 @@ import "math"
 //    IEEE      -10,+10   1,000,000     2.9e-16     6.1e-17

 // Sqrt returns the square root of x.
+// The result r is chosen so that real(r) ≥ 0 and imag(r) has the same sign as imag(x).
 func Sqrt(x complex128) complex128 {
 	if imag(x) == 0 {
 		if real(x) == 0 {