/complex.go

  1// Copyright 2009 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/* This package implements some basic functionality for
  6   complex numbers. 
  7
  8	Add
  9
 10*/
 11
 12package complex
 13
 14import "math"
 15
 16type Complex struct {
 17	real	float64;
 18	im	float64;
 19}
 20
 21func NewComplex(_real, _im float64) *Complex {
 22	c := new(Complex);
 23	c.real = _real;
 24	c.im = _im;
 25	return c;
 26}
 27
 28// Returns the absolute value
 29func Abs(z *Complex) float64 {
 30	sq := (z.real * z.real) + (z.im * z.im);
 31	result := math.Sqrt(sq);
 32	return result;
 33}
 34
 35// Returns the conjugate
 36func Conj(z *Complex) *Complex {
 37	result := NewComplex(z.real, -(z.im));
 38	return result;
 39}
 40
 41// Adds another complex to this complex (similar to "+=" operator)
 42func (c *Complex) AddTo(b *Complex) {
 43	c.real += b.real;
 44	c.im += b.im;
 45}
 46
 47// Adds two complex numbers together to make a third complex
 48func Add(a, b *Complex) *Complex {
 49	c := NewComplex(a.real, a.im);
 50	c.AddTo(b);
 51	return c;
 52}
 53
 54// Subtracts another complex from this complex (similar to "-=" operator)
 55func (c *Complex) SubFrom(b *Complex) {
 56	c.real -= b.real;
 57	c.im -= b.im;
 58}
 59
 60// Subtracts one complex from another to make a third complex
 61func Sub(a, b *Complex) *Complex {
 62	c := NewComplex(a.real, a.im);
 63	c.SubFrom(b);
 64	return c;
 65}
 66
 67// Multiplies this complex by another complex (similar to "*=" operator)
 68func (c *Complex) MultBy(b *Complex) {
 69	re := (c.real * b.real) - (c.im * b.im);
 70	im := (c.real * b.im) + (c.im * b.real);
 71	c.real -= re;
 72	c.im -= im;
 73}
 74
 75// Multiplies one complex by another to make a third complex
 76func Mult(a, b *Complex) *Complex {
 77	re := (a.real * b.real) - (a.im * b.im);
 78	im := (a.real * b.im) + (a.im * b.real);
 79	c := NewComplex(re, im);
 80	return c;
 81}
 82
 83// Divides this complex by another complex (similar to "/=" operator)
 84// TODO
 85func (c *Complex) DivBy(b *Complex) {
 86	re := (c.real * b.real) - (c.im * b.im);
 87	im := (c.real * b.im) + (c.im * b.real);
 88	c.real -= re;
 89	c.im -= im;
 90}
 91
 92// Multiplies one complex by another to make a third complex
 93// TODO
 94func Div(a, b *Complex) *Complex {
 95	re := (a.real * b.real) - (a.im * b.im);
 96	im := (a.real * b.im) + (a.im * b.real);
 97	c := NewComplex(re, im);
 98	return c;
 99}
100
101