Imported Upstream version 1.4upstream/1.4

1 files changed, 25 insertions, 0 deletions

diff --git a/src/math/cmplx/isnan.go b/src/math/cmplx/isnan.go
new file mode 100644
index 000000000..05d0cce63
--- /dev/null
+++ b/src/math/cmplx/isnan.go
@@ -0,0 +1,25 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cmplx
+
+import "math"
+
+// IsNaN returns true if either real(x) or imag(x) is NaN
+// and neither is an infinity.
+func IsNaN(x complex128) bool {
+	switch {
+	case math.IsInf(real(x), 0) || math.IsInf(imag(x), 0):
+		return false
+	case math.IsNaN(real(x)) || math.IsNaN(imag(x)):
+		return true
+	}
+	return false
+}
+
+// NaN returns a complex ``not-a-number'' value.
+func NaN() complex128 {
+	nan := math.NaN()
+	return complex(nan, nan)
+}