Mercurial > hg > CbC > CbC_gcc
view libgo/go/math/hypot.go @ 158:494b0b89df80 default tip
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author | Shinji KONO <kono@ie.u-ryukyu.ac.jp> |
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date | Mon, 25 May 2020 18:13:55 +0900 |
parents | 84e7813d76e9 |
children |
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// 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 math /* Hypot -- sqrt(p*p + q*q), but overflows only if the result does. */ // Hypot returns Sqrt(p*p + q*q), taking care to avoid // unnecessary overflow and underflow. // // Special cases are: // Hypot(±Inf, q) = +Inf // Hypot(p, ±Inf) = +Inf // Hypot(NaN, q) = NaN // Hypot(p, NaN) = NaN func Hypot(p, q float64) float64 { return hypot(p, q) } func hypot(p, q float64) float64 { // special cases switch { case IsInf(p, 0) || IsInf(q, 0): return Inf(1) case IsNaN(p) || IsNaN(q): return NaN() } p, q = Abs(p), Abs(q) if p < q { p, q = q, p } if p == 0 { return 0 } q = q / p return p * Sqrt(1+q*q) }