golang abs 代码
文件路径：/src/math/cmplx/abs.go
/ 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 cmplx provides basic constants and mathematical functions for
/ complex numbers. Special case handling conforms to the C99 standard
/ Annex G IEC 60559-compatible complex arithmetic.
package cmplx
import "math"
/ Abs returns the absolute value (also called the modulus) of x.
func Abs(x complex128) float64 { return math.Hypot(real(x), imag(x)) }