diff options
author | Daniil Cherednik <dan.cherednik@gmail.com> | 2022-11-24 13:14:34 +0300 |
---|---|---|
committer | Daniil Cherednik <dan.cherednik@gmail.com> | 2022-11-24 14:46:00 +0300 |
commit | 87f7fceed34bcafb8aaff351dd493a35c916986f (patch) | |
tree | 26809ec8f550aba8eb019e59adc3d48e51913eb2 /contrib/go/_std_1.18/src/math/sinh.go | |
parent | 11bc4015b8010ae201bf3eb33db7dba425aca35e (diff) | |
download | ydb-87f7fceed34bcafb8aaff351dd493a35c916986f.tar.gz |
Ydb stable 22-4-4322.4.43
x-stable-origin-commit: 8d49d46cc834835bf3e50870516acd7376a63bcf
Diffstat (limited to 'contrib/go/_std_1.18/src/math/sinh.go')
-rw-r--r-- | contrib/go/_std_1.18/src/math/sinh.go | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/contrib/go/_std_1.18/src/math/sinh.go b/contrib/go/_std_1.18/src/math/sinh.go new file mode 100644 index 0000000000..9fe9b4e17a --- /dev/null +++ b/contrib/go/_std_1.18/src/math/sinh.go @@ -0,0 +1,91 @@ +// 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 sine and cosine. + + The exponential func is called for arguments + greater in magnitude than 0.5. + + A series is used for arguments smaller in magnitude than 0.5. + + Cosh(x) is computed from the exponential func for + all arguments. +*/ + +// Sinh returns the hyperbolic sine of x. +// +// Special cases are: +// Sinh(±0) = ±0 +// Sinh(±Inf) = ±Inf +// Sinh(NaN) = NaN +func Sinh(x float64) float64 { + if haveArchSinh { + return archSinh(x) + } + return sinh(x) +} + +func sinh(x float64) float64 { + // The coefficients are #2029 from Hart & Cheney. (20.36D) + const ( + P0 = -0.6307673640497716991184787251e+6 + P1 = -0.8991272022039509355398013511e+5 + P2 = -0.2894211355989563807284660366e+4 + P3 = -0.2630563213397497062819489e+2 + Q0 = -0.6307673640497716991212077277e+6 + Q1 = 0.1521517378790019070696485176e+5 + Q2 = -0.173678953558233699533450911e+3 + ) + + sign := false + if x < 0 { + x = -x + sign = true + } + + var temp float64 + switch { + case x > 21: + temp = Exp(x) * 0.5 + + case x > 0.5: + ex := Exp(x) + temp = (ex - 1/ex) * 0.5 + + default: + sq := x * x + temp = (((P3*sq+P2)*sq+P1)*sq + P0) * x + temp = temp / (((sq+Q2)*sq+Q1)*sq + Q0) + } + + if sign { + temp = -temp + } + return temp +} + +// Cosh returns the hyperbolic cosine of x. +// +// Special cases are: +// Cosh(±0) = 1 +// Cosh(±Inf) = +Inf +// Cosh(NaN) = NaN +func Cosh(x float64) float64 { + if haveArchCosh { + return archCosh(x) + } + return cosh(x) +} + +func cosh(x float64) float64 { + x = Abs(x) + if x > 21 { + return Exp(x) * 0.5 + } + ex := Exp(x) + return (ex + 1/ex) * 0.5 +} |