github.com/zebozhuang/go@v0.0.0-20200207033046-f8a98f6f5c5d/src/math/cmplx/phase.go (about)

     1  // Copyright 2010 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package cmplx
     6  
     7  import "math"
     8  
     9  // Phase returns the phase (also called the argument) of x.
    10  // The returned value is in the range [-Pi, Pi].
    11  func Phase(x complex128) float64 { return math.Atan2(imag(x), real(x)) }