From 5ff4c17907d5b19510a62e08fd8d3b11e62b431d Mon Sep 17 00:00:00 2001 From: Ondřej Surý Date: Tue, 13 Sep 2011 13:13:40 +0200 Subject: Imported Upstream version 60 --- src/pkg/math/tanh.go | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) create mode 100644 src/pkg/math/tanh.go (limited to 'src/pkg/math/tanh.go') diff --git a/src/pkg/math/tanh.go b/src/pkg/math/tanh.go new file mode 100644 index 000000000..f4a8a5a4d --- /dev/null +++ b/src/pkg/math/tanh.go @@ -0,0 +1,27 @@ +// Copyright 2009 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 math + +/* + Floating-point hyperbolic tangent. + + Sinh and Cosh are called except for large arguments, which + would cause overflow improperly. +*/ + +// Tanh computes the hyperbolic tangent of x. +func Tanh(x float64) float64 { + if x < 0 { + x = -x + if x > 21 { + return -1 + } + return -Sinh(x) / Cosh(x) + } + if x > 21 { + return 1 + } + return Sinh(x) / Cosh(x) +} -- cgit v1.2.3