JSci.maths.wavelet.Sine Maven / Gradle / Ivy

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JSci is a set of open source Java packages. The aim is to encapsulate scientific methods/principles in the most natural way possible. As such they should greatly aid the development of scientific based software. It offers: abstract math interfaces, linear algebra (support for various matrix and vector types), statistics (including probability distributions), wavelets, newtonian mechanics, chart/graph components (AWT and Swing), MathML DOM implementation, ... Note: some packages, like javax.comm, for the astro and instruments package aren't listed as dependencies (not available).

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package JSci.maths.wavelet;

import JSci.maths.wavelet.*;
import JSci.maths.*;

/**********************************************
* This class is used to be able to mix the wavelet
* and sine transforms. It is in fact a normalised
* sine.
* @author Daniel Lemire
*************************************************/
public final class Sine extends MultiscaleFunction implements NumericalConstants, Cloneable  {

		private int n0; private int freq;private double normalisation;

  /*******************************
  * Return a String representation
  * of the object
  ********************************/
  public String toString() {
    String ans=new String("[n0=");
    ans.concat(Integer.toString(n0));
    ans.concat("][freq=");
    ans.concat(Integer.toString(freq));
    ans.concat("]");
    return(ans);
  }

  public Sine (int N0,int FREQ) {
			if(N0<0) {
				throw new IllegalArgumentException("The length paramenter "+N0+" must be positive");
			}
			if((FREQ<0)||(FREQ>=N0)) {
				throw new IllegalArgumentException("The frequency parameter "+FREQ+" must be between "+0+" and "+(N0-1));
			}
			n0=N0;freq=FREQ;
			normalisation=Math.sqrt(n0/2d);

		}

  /*****************************************
  * Check if another object is equal to this
  * Sine object
  ******************************************/
  public boolean equals(Object a) {
    if((a!=null) && (a instanceof Sine))  {
      Sine iv=(Sine)a;
      return (this.dimension(0)==iv.dimension(0)) && (this.getFrequency()==iv.getFrequency());
    }
    return false;
  }

  public int getFrequency() {
    return(freq);
  }


	/************************************************
  * Return as an array the sampled values
  * of the function
	*************************************************/
		public double[] evaluate() {
			return(ArrayMath.scalarMultiply(1.0/normalisation,evaluate(n0,freq)));
		}

	private static double[] evaluate(int N0,int FREQ) {
			double[] ans=new double[N0];
			for(int k=0;k