/**
* 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 Daub02.java is part of JWave.
*
* @author Christian Scheiblich
* date 23.02.2010 05:42:23
* contact graetz@mailfish.de
*/
package math.transform.jwave.handlers.wavelets;
/**
* Ingrid Daubechies' orthonormal wavelet of four coefficients and the scales;
* normed, due to ||*||2 - euclidean norm.
*
* @date 10.02.2010 15:42:45
* @author Christian Scheiblich
*/
public class Daub02 extends Wavelet {
/**
* Constructor setting up the orthonormal Daubechie4 wavelet coeffs and the
* scales; normed, due to ||*||2 - euclidean norm.
*
* @date 10.02.2010 15:42:45
* @author Christian Scheiblich
*/
public Daub02( ) {
_waveLength = 4;
_scales = new double[ _waveLength ]; // can be done in static way also; faster?
double sqrt3 = Math.sqrt( 3. ); // 1.7320508075688772
_scales[ 0 ] = ( ( 1. + sqrt3 ) / 4. ) / 1.4142135623730951;
_scales[ 1 ] = ( ( 3. + sqrt3 ) / 4. ) / 1.4142135623730951;
_scales[ 2 ] = ( ( 3. - sqrt3 ) / 4. ) / 1.4142135623730951;
_scales[ 3 ] = ( ( 1. - sqrt3 ) / 4. ) / 1.4142135623730951;
_coeffs = new double[ _waveLength ]; // can be done in static way also; faster?
_coeffs[ 0 ] = _scales[ 3 ]; // h3
_coeffs[ 1 ] = -_scales[ 2 ]; // -h2
_coeffs[ 2 ] = _scales[ 1 ]; // h1
_coeffs[ 3 ] = -_scales[ 0 ]; // -h0
} // Daub02
} // class