Java/計算機科学/その他/複素数 - mattyalib @ ウィキ

複素数

public class Complex {
	public double re;
	public double im;
 
	public static Complex ZERO = new Complex(0.0, 0.0);
	public static Complex ONE = new Complex(1.0, 0.0);
	public static Complex I = new Complex(0.0, 1.0);
	public static Complex NaN = new Complex(Double.NaN, Double.NaN);
 
	public Complex(double r, double i){
		re = r; im = i;
	}
	public Complex(double theta){
		re = Math.cos(theta);
		im = Math.sin(theta);
	}
	public Complex(Complex z){
		re = z.re; im = z.im;
	}
 
	public String toString() {
		DecimalFormat df = new DecimalFormat(" ##0.000;-##0.000");
		StringBuffer sb = new StringBuffer();
		sb.append(df.format(re));
		sb.append(" ");
		sb.append(df.format(im));
		return sb.toString();
	}
 
	public double re(){ return re; }
	public double im(){ return im; }
 
	public Complex copy(){
		return new Complex(re,im);
	}
	public Complex add(Complex z){
		return new Complex(re+z.re, im+z.im);
	}
	public Complex sub(Complex z){
		return new Complex(re-z.re, im-z.im);
	}
	public Complex mul(Complex z){
		return new Complex(re*z.re-im*z.im, re*z.im+im*z.re);
	}
	public Complex mul(double k){
		return new Complex(k*re, k*im);
	}
	public Complex div(Complex z){
		double tmp = z.norm();
		return new Complex((re*z.re+im*z.im)/tmp, (-re*z.im+im*z.re)/tmp);
	}
	public Complex conj(){
		return new Complex(re,-im);
	}
	public Complex sqr(){
		return this.mul(this);
	}
	public void addeq(Complex z){
		re += z.re;
		im += z.im;
	}
	public void subeq(Complex z){
		re -= z.re;
		im -= z.im;
	}
	public void muleq(Complex z){
		double tmp = re*z.re - im*z.im;
		im = re*z.im + im*z.re;
		re = tmp;
	}
	public void diveq(Complex z){
		double tmp = z.norm();
		this.muleq(conj(z));
		this.muleq(1.0/tmp);
	}
	public void muleq(double a){
		re *= a;
		im *= a;
	}
	public void conjeq(){
		im *= -1.0;
	}
 
	public double abs(){
		return Math.hypot(re, im);
	}
	public double norm(){
		return re*re + im*im;
	}
	public double arg(){
		return Math.atan2(im, re);
	}
 
	public static Complex add(Complex x, Complex y){
		return new Complex(x.re+y.re, x.im+y.im);
	}
	public static Complex sub(Complex x, Complex y){
		return new Complex(x.re-y.re, x.im-y.im);
	}
	public static Complex mul(Complex x, Complex y){
		return new Complex(x.re*y.re - x.im*y.im, x.re*y.im + x.im*y.re);
	}
	public static Complex div(Complex x, Complex y){
		return new Complex(x.re+y.re, x.im+y.im);
	}
	public static Complex mul(double a, Complex x){
		return new Complex(a*x.re, a*x.im);
	}
	public static Complex conj(Complex x){
		return new Complex(x.re, -x.im);
	}
 
	public static double abs(Complex z){
		return Math.hypot(z.re, z.im);
	}
	public static double norm(Complex z){
		return z.re*z.re + z.im*z.im;
	}
	public static double arg(Complex z){
		return Math.atan2(z.im, z.re);
	}
 
	public void print(){
		System.out.println(re + "+" + im + "i");
	}
 
}