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/*
* Copyright 2013 Phil Burk, Mobileer Inc
*
* 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.
*/
package com.jsyn.data;
import com.jsyn.unitgen.SpectralFFT;
import com.jsyn.unitgen.SpectralIFFT;
import com.jsyn.unitgen.SpectralProcessor;
/**
* Complex spectrum with real and imaginary parts. The frequency associated with each bin of the
* spectrum is:
*
* <pre>
* frequency = binIndex * sampleRate / size
* </pre>
*
* Note that the upper half of the spectrum is above the Nyquist frequency. Those frequencies are
* mirrored around the Nyquist frequency. Note that this spectral API is experimental and may change
* at any time.
*
* @author Phil Burk (C) 2013 Mobileer Inc
* @version 016
* @see SpectralFFT
* @see SpectralIFFT
* @see SpectralProcessor
*/
public class Spectrum {
private double[] real;
private double[] imaginary;
public static final int DEFAULT_SIZE_LOG_2 = 9;
public static final int DEFAULT_SIZE = 1 << DEFAULT_SIZE_LOG_2;
public Spectrum() {
this(DEFAULT_SIZE);
}
public Spectrum(int size) {
setSize(size);
}
public double[] getReal() {
return real;
}
public double[] getImaginary() {
return imaginary;
}
/**
* If you change the size of the spectrum then the real and imaginary arrays will be
* reallocated.
*
* @param size
*/
public void setSize(int size) {
if ((real == null) || (real.length != size)) {
real = new double[size];
imaginary = new double[size];
}
}
public int size() {
return real.length;
}
/**
* Copy this spectrum to another spectrum of the same length.
*
* @param destination
*/
public void copyTo(Spectrum destination) {
assert (size() == destination.size());
System.arraycopy(real, 0, destination.real, 0, real.length);
System.arraycopy(imaginary, 0, destination.imaginary, 0, imaginary.length);
}
public void clear() {
for (int i = 0; i < real.length; i++) {
real[i] = 0.0;
imaginary[i] = 0.0;
}
}
}
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