From 1d4e2d1adc9884d97ab3fc9e2766441f2de7d554 Mon Sep 17 00:00:00 2001 From: "Charles L. Dorian" Date: Sat, 15 May 2010 10:06:54 -0700 Subject: [PATCH] cmath: add package description Also update range of Phase and Polar due to signed zero. [Phase(cmplx(-1, +0)) = pi and Phase(cmplx(-1, -0)) = -pi] R=rsc, r CC=golang-dev https://golang.org/cl/1235041 --- src/pkg/cmath/abs.go | 2 ++ src/pkg/cmath/phase.go | 2 +- src/pkg/cmath/polar.go | 2 +- 3 files changed, 4 insertions(+), 2 deletions(-) diff --git a/src/pkg/cmath/abs.go b/src/pkg/cmath/abs.go index 30995cec60..725dc4e982 100644 --- a/src/pkg/cmath/abs.go +++ b/src/pkg/cmath/abs.go @@ -2,6 +2,8 @@ // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. +// The cmath package provides basic constants +// and mathematical functions for complex numbers. package cmath import "math" diff --git a/src/pkg/cmath/phase.go b/src/pkg/cmath/phase.go index 97a4834927..2d67aa34c7 100644 --- a/src/pkg/cmath/phase.go +++ b/src/pkg/cmath/phase.go @@ -7,5 +7,5 @@ package cmath import "math" // Phase returns the phase (also called the argument) of x. -// The returned value is in the range (-Pi, Pi]. +// The returned value is in the range [-Pi, Pi]. func Phase(x complex128) float64 { return math.Atan2(imag(x), real(x)) } diff --git a/src/pkg/cmath/polar.go b/src/pkg/cmath/polar.go index f55aef42b0..033676acc5 100644 --- a/src/pkg/cmath/polar.go +++ b/src/pkg/cmath/polar.go @@ -6,7 +6,7 @@ package cmath // Polar returns the absolute value r and phase θ of x, // such that x = r * e**θi. -// The phase is in the range (-Pi, Pi]. +// The phase is in the range [-Pi, Pi]. func Polar(x complex128) (r, θ float64) { return Abs(x), Phase(x) } -- 2.50.0