| // 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 |
| |
| |
| /* |
| * tanh(x) computes the hyperbolic tangent of its floating |
| * point argument. |
| * |
| * 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); |
| } |