//===========================================================================//= References:                                                             =//=-------------------------------------------------------------------------=//= Module history:                                                         =//= - June 8 2005 - Oscar Chavarro: Original base version                   =//=-------------------------------------------------------------------------=//= [.wPRIN2007] Princeton University, "Introduction to programming in      =//=     Java", course notes available at                                    =//=     http://www.cs.princeton.edu/introcs/97data/                         =//=     last accessed, june 8 2007.                                         =//===========================================================================package vsdk.toolkit.common;import vsdk.toolkit.common.VSDK;/**A complex child is one with a real mother and an imaginary father.Current implementation of complex number based on (borrowed from, jeje)sample in [.wPRIN2007].9 course notes.*/public class Complex extends FundamentalEntity {    /// Check the general attribute description in superclass Entity.    public static final long serialVersionUID = 20070712L;    /// Current complex number real part    public double r;    /// Current complex number imaginary part    public double i;    /**    Create a new object with the given real and imaginary parts    */    public Complex(double real, double imag) {        r = real;        i = imag;    }    /**    Return abs/modulus/magnitude    */    public double abs() {        return Math.hypot(r, i); // Math.sqrt(r*r + i*i)    }    /**    Return angle/phase/argument    */    public double phase() {        // between -pi and pi        return Math.atan2(i, r);    }    /**    Return a new Complex object whose value is (this + b)    */    public Complex plus(Complex b) {        double real = this.r + b.r;        double imag = this.i + b.i;        return new Complex(real, imag);    }    /**    Return a new Complex object whose value is (this - b)    */    public Complex minus(Complex b) {        Complex a = this;        double real = a.r - b.r;        double imag = a.i - b.i;        return new Complex(real, imag);    }    /**    Return a new Complex object whose value is (this * b)    */    public Complex times(Complex b) {        Complex a = this;        double real = a.r * b.r - a.i * b.i;        double imag = a.r * b.i + a.i * b.r;        return new Complex(real, imag);    }    /**    Scalar multiplication    Return a new object whose value is (this * alpha)    */    public Complex times(double alpha) {        return new Complex(alpha * r, alpha * i);    }    /**    Return a new Complex object whose value is the conjugate of this    */    public Complex conjugate() {      return new Complex(r, -i);    }    /**    Return a new Complex object whose value is the reciprocal of this    */    public Complex reciprocal() {        double scale = r*r + i*i;        return new Complex(r / scale, -i / scale);    }    /**    Return a / b    */    public Complex divides(Complex b) {        Complex a = this;        return a.times(b.reciprocal());    }    /**    Return a new Complex object whose value is the complex exponential of this    */    public Complex exp() {        return new Complex(Math.exp(r) * Math.cos(i), Math.exp(r) * Math.sin(i));    }    /**    Return a new Complex object whose value is the complex sine of this    */    public Complex sin() {        return new Complex(Math.sin(r) * Math.cosh(i), Math.cos(r) * Math.sinh(i));    }    /**    Return a new Complex object whose value is the complex cosine of this    */    public Complex cos() {        return new Complex(Math.cos(r) * Math.cosh(i), -Math.sin(r) * Math.sinh(i));    }    /**    Return a new Complex object whose value is the complex tangent of this    */    public Complex tan() {        return sin().divides(cos());    }    /**    A static version of plus    */    public static Complex plus(Complex a, Complex b) {        double real = a.r + b.r;        double imag = a.i + b.i;        Complex sum = new Complex(real, imag);        return sum;    }    /**    Return a string representation of the invoking Complex object    */    public String toString() {        if ( i <  0 ) {            return VSDK.formatDouble(r) + " - " + VSDK.formatDouble(-i) + "i";        }        return VSDK.formatDouble(r) + " + " + VSDK.formatDouble(i) + "i";    }}//===========================================================================//= EOF                                                                     =//===========================================================================