33 lines
611 B
Go
33 lines
611 B
Go
// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package math
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/*
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Floating-point hyperbolic tangent.
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Sinh and Cosh are called except for large arguments, which
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would cause overflow improperly.
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*/
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// Tanh computes the hyperbolic tangent of x.
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//
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// Special cases are:
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// Tanh(±0) = ±0
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// Tanh(±Inf) = ±1
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// Tanh(NaN) = NaN
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func Tanh(x float64) float64 {
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if x < 0 {
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x = -x
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if x > 21 {
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return -1
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}
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return -Sinh(x) / Cosh(x)
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}
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if x > 21 {
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return 1
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}
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return Sinh(x) / Cosh(x)
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}
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