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/** A class to represent Complex Numbers. A Complex object is
* immutable once created; the add, subtract and multiply routines
* return newly-created Complex objects containing the results.
*
* @author Ian F. Darwin, inspired by David Flanagan.
* @version $Id: Complex.java,v 1.3 2004/05/13 22:28:59 ian Exp $
*/
public class Complex {
/** The real part */
private double r;
/** The imaginary part */
private double i;
/** Construct a Complex */
Complex(double rr, double ii) {
r = rr;
i = ii;
}
/** Display the current Complex as a String, for use in
* println() and elsewhere.
*/
public String toString() {
StringBuffer sb = new StringBuffer().append(r);
if (i>0)
sb.append('+'); // else append(i) appends - sign
return sb.append(i).append('i').toString();
}
/** Return just the Real part */
public double getReal() {
return r;
}
/** Return just the Real part */
public double getImaginary() {
return i;
}
/** Return the magnitude of a complex number */
public double magnitude() {
return Math.sqrt(r*r + i*i);
}
/** Add another Complex to this one
*/
public Complex add(Complex other) {
return add(this, other);
}
/** Add two Complexes
*/
public static Complex add(Complex c1, Complex c2) {
return new Complex(c1.r+c2.r, c1.i+c2.i);
}
/** Subtract another Complex from this one
*/
public Complex subtract(Complex other) {
return subtract(this, other);
}
/** Subtract two Complexes
*/
public static Complex subtract(Complex c1, Complex c2) {
return new Complex(c1.r-c2.r, c1.i-c2.i);
}
/** Multiply this Complex times another one
*/
public Complex multiply(Complex other) {
return multiply(this, other);
}
/** Multiply two Complexes
*/
public static Complex multiply(Complex c1, Complex c2) {
return new Complex(c1.r*c2.r - c1.i*c2.i, c1.r*c2.i + c1.i*c2.r);
}
/** Divide c1 by c2.
* @author Gisbert Selke.
*/
public static Complex divide(Complex c1, Complex c2) {
return new Complex(
(c1.r*c2.r+c1.i*c2.i)/(c2.r*c2.r+c2.i*c2.i),
(c1.i*c2.r-c1.r*c2.i)/(c2.r*c2.r+c2.i*c2.i));
}
/* Compare this Complex number with another
*/
public boolean equals(Object o) {
if (!(o instanceof Complex))
throw new IllegalArgumentException(
"Complex.equals argument must be a Complex");
Complex other = (Complex)o;
return r == other.r && i == other.i;
}
/* Generate a hashCode; not sure how well distributed these are.
*/
public int hashCode() {
return (int)( r) | (int)i;
}
public static void main(String[] args) {
Complex c = new Complex(3, 5);
Complex d = new Complex(2, -2);
System.out.println(c);
System.out.println(c + ".getReal() = " + c.getReal());
System.out.println(c + " + " + d + " = " + c.add(d));
System.out.println(c + " + " + d + " = " + Complex.add(c, d));
System.out.println(c + " * " + d + " = " + c.multiply(d));
System.out.println(Complex.divide(c, d));
}
}
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