/**
* JWave - Java implementation of wavelet transform algorithms
*
* Copyright 2010-2012 Christian Scheiblich
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* This file Complex.java is part of JWave.
*
* @author Christian Scheiblich
* date 19.11.2010 13:20:28
* contact graetz@mailfish.de
*/
package math.jwave.datatypes;
/**
* A class to represent a Complex Number. A Complex object is immutable once
* created; the add, subtract and multiply routines return newly-created Complex
* objects containing each requested result.
*
* @date 19.11.2010 13:20:48
* @author Christian Scheiblich
*/
public class Complex {
/**
* The real number.
*/
private double _r;
/**
* The imaginary number.
*/
private double _j;
/**
* Standard constructor.
*
* @date 19.11.2010 13:38:56
* @author Christian Scheiblich
*/
public Complex( ) {
_r = 0.;
_j = 0.;
} // Complex
/**
* Copy constructor.
*
* @date 19.11.2010 13:22:54
* @author Christian Scheiblich
* @param c
* complex number
*/
public Complex( Complex c ) {
_r = c._r;
_j = c._j;
} // Complex
/**
* Constructor taking real and imaginary number.
*
* @date 19.11.2010 13:21:48
* @author Christian Scheiblich
* @param r
* real number
* @param j
* imaginary number
*/
public Complex( double r, double j ) {
_r = r;
_j = j;
} // Complex
/**
* Display the current Complex as a String, for usage in println( ) and
* elsewhere.
*
* @date 19.11.2010 13:23:13
* @author Christian Scheiblich
*/
@Override
public String toString( ) {
StringBuffer sb = new StringBuffer( ).append( _r );
if( _j > 0 )
sb.append( '+' ); // else append(i) appends - sign
return sb.append( _j ).append( 'j' ).toString( );
} // toString
/**
* Return the real number.
*
* @date 19.11.2010 13:23:34
* @author Christian Scheiblich
* @return real number of this complex number
*/
public double getReal( ) {
return _r;
} // getReal( )
/**
* Return the imaginary number.
*
* @date 19.11.2010 13:23:51
* @author Christian Scheiblich
* @return imaginary number of this complex number
*/
public double getImag( ) {
return _j;
} // getImag
/**
* Set the real number.
*
* @date 23.11.2010 18:44:52
* @author Christian Scheiblich
* @param r
* the real number
*/
public void setReal( double r ) {
_r = r;
} // setReal
/**
* Set the imaginary number.
*
* @date 23.11.2010 18:45:16
* @author Christian Scheiblich
* @param j
* the imaginary number
*/
public void setImag( double j ) {
_j = j;
} // setImag
/**
* Add to real number.
*
* @date 23.11.2010 18:49:57
* @author Christian Scheiblich
* @param r
* the real number
*/
public void addReal( double r ) {
_r += r;
} // addReal
/**
* Add to imaginary number.
*
* @date 23.11.2010 18:50:23
* @author Christian Scheiblich
* @param j
* the imaginary number
*/
public void addImag( double j ) {
_j += j;
} // addImag
/**
* multiply scalar to real number.
*
* @date 23.11.2010 18:53:27
* @author Christian Scheiblich
* @param s
* scalar
*/
public void mulReal( double s ) {
_r *= s;
} // mulReal
/**
* multiply scalar to imaginary number.
*
* @date 23.11.2010 18:54:48
* @author Christian Scheiblich
* @param s
* scalar
*/
public void mulImag( double s ) {
_j *= s;
} // mulImag
/**
* Calculate the magnitude of the complex number.
*
* @date 19.11.2010 13:24:28
* @author Christian Scheiblich
* @return magnitude of this complex number
*/
public double getMag( ) {
return Math.sqrt( _r * _r + _j * _j );
} // getMag( )
/**
* Calculates the angle phi of a complex number.
*
* @date 19.11.2010 13:24:48
* @author Christian Scheiblich
* @return angle of this complex number
*/
public double getPhi( ) {
if( _r == 0. && _j == 0 )
return 0.;
double phi = Math.toDegrees( Math.atan( Math.abs( _j / _r ) ) );
if( _r >= 0. && _j >= 0. ) // 1. quadrant
return phi;
if( _r <= 0. && _j >= 0. ) // 2. quadrant
return 180. - phi;
if( _r <= 0. && _j <= 0. ) // 3. quadrant
return phi + 180.;
if( _r >= 0. && _j <= 0. ) // 4. quadrant
return 360. - phi;
return Math.toDegrees( Math.atan( Math.abs( _j / _r ) ) );
} // getPhi( )
/**
* Returns the stored values as new double array: [ real, imag ].
*
* @date 19.11.2010 13:25:38
* @author Christian Scheiblich
* @return returns stored values as array [ real, imag ]
*/
public double[ ] toArr( ) {
double[ ] arr = {
_r, _j
};
return arr;
} // toArr
/**
* Returns the conjugate complex number of this complex number.
*
* @date 19.11.2010 19:36:52
* @author Thomas Leduc
* @return new object of Complex keeping the result
*/
public Complex conjugate( ) {
return new Complex( _r, -_j );
} // conjugate
/**
* Add another complex number to this one and return.
*
* @date 19.11.2010 13:25:55
* @author Christian Scheiblich
* @param c
* complex number
* @return new object of Complex keeping the result
*/
public Complex add( Complex c ) {
return new Complex( _r + c._r, _j + c._j );
} // add
/**
* Subtract another complex number from this one.
*
* @date 19.11.2010 13:27:05
* @author Christian Scheiblich
* @param c
* complex number
* @return new object of Complex keeping the result
*/
public Complex sub( Complex c ) {
return new Complex( _r - c._r, _j - c._j );
} // sub
/**
* Multiply this complex number times another one.
*
* @date 19.11.2010 13:27:36
* @author Christian Scheiblich
* @param c
* complex number
* @return new object of Complex keeping the result
*/
public Complex mul( Complex c ) {
return new Complex( _r * c._r - _j * c._j, _r * c._j + _j * c._r );
} // mul
/**
* Multiply this complex number times a scalar.
*
* @date 19.11.2010 13:28:03
* @author Christian Scheiblich
* @param s
* scalar
* @return new object of Complex keeping the result
*/
public Complex mul( double s ) {
return new Complex( _r * s, _j * s );
} // mul
/**
* Divide this complex number by another one.
*
* @date 19.11.2010 19:45:02
* @author Thomas Leduc
* @param c
* complex number
* @return new object of Complex keeping the result
*/
public Complex div( Complex c ) {
return mul( c.conjugate( ) ).div( c._r * c._r + c._j * c._j );
} // div
/**
* Divide this complex number by a scalar.
*
* @date 19.11.2010 13:29:49
* @author Thomas Leduc
* @param s
* scalar
* @return new object of Complex keeping the result
*/
public Complex div( double s ) {
return mul( 1. / s );
} // div
/**
* Generates a hash code for this object.
*
* @date 19.11.2010 19:42:39
* @author Thomas Leduc
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode( ) {
final int prime = 31;
int result = 1;
long temp;
temp = Double.doubleToLongBits( _j );
result = prime * result + (int)( temp ^ ( temp >>> 32 ) );
temp = Double.doubleToLongBits( _r );
result = prime * result + (int)( temp ^ ( temp >>> 32 ) );
return result;
} // hashCode
/**
* Compare this Complex number with another one.
*
* @date 19.11.2010 13:30:35
* @author Thomas Leduc
* @see java.lang.Object#equals(java.lang.Object)
*/
@Override
public boolean equals( Object obj ) {
if( this == obj )
return true;
if( obj == null )
return false;
if( getClass( ) != obj.getClass( ) )
return false;
Complex other = (Complex)obj;
if( Double.doubleToLongBits( _j ) != Double.doubleToLongBits( other._j ) )
return false;
if( Double.doubleToLongBits( _r ) != Double.doubleToLongBits( other._r ) )
return false;
return true;
} // equals
/**
* Print this complex number to console.
*
* @date 19.11.2010 13:31:16
* @author Christian Scheiblich
*/
public void show( ) {
if( _j < 0 )
System.out.println( getReal( ) + " - j" + Math.abs( getImag( ) ) );
else
System.out.println( getReal( ) + " + j" + getImag( ) );
} // show
/**
* Print this complex number to console with an identifier before.
*
* @date 19.11.2010 13:31:32
* @author Christian Scheiblich
* @param ident
* string to label this complex number
*/
public void show( String ident ) {
if( _j < 0 )
System.out.println( ident + ": " + getReal( ) + " - j" + Math.abs( getImag( ) ) );
else
System.out.println( ident + ": " + getReal( ) + " + j" + getImag( ) );
} // show
/**
* Print magnitude to console out.
*
* @date 19.11.2010 13:32:15
* @author Christian Scheiblich
*/
public void showMag( ) {
System.out.println( getMag( ) );
} // showMag
/**
* Print angle to console out.
*
* @date 19.11.2010 13:32:33
* @author Christian Scheiblich
*/
public void showPhi( ) {
System.out.println( getPhi( ) );
} // showPhi
} // class
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