org.nevec.prima.simulator.fluctuations
Class Fluctuation

java.lang.Object
  org.nevec.prima.simulator.fluctuations.Fluctuation

public class Fluctuation
extends Object

This class computes fluctuations which follow a given power density spectrum. It may be used for computing atmospheric fluctuations.

Version:

$Id: Fluctuation.java,v 1.1 2006/03/15 10:44:10 jdejong Exp $

Field Summary

private Complex[]	a Amplitudes
double	dt Size of time bins
private FFT	fft Performs FFT
double[]	filterFunc For diagnostic purposes
private ArrayList<PowerFilter>	filters Defines the spectral filters to be used
double[]	freq
double[]	phase Phase
double[]	power Power spectrum

Constructor Summary

Fluctuation(int length, double dt)

Method Summary

void	addFilter(PowerFilter filter)
void	filter() Applies the defined filter functions to the spectrum
double[][]	getTimeSeries() Retrieve the time series, which has been obtained by an inverse FFT
void	inverse() Obtain a new time series from the spectrum by means of an inverse FFT
void	newRandomDist() Creates new random distribution of a normalized amplitude
void	newSeries() Does all the steps in a single go
void	newSpectrum() Creates a new spectrum from the time series
void	removeFilters()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

a

private Complex[] a

Amplitudes

power

public double[] power

Power spectrum

phase

public double[] phase

Phase

freq

public double[] freq

dt

public double dt

Size of time bins

filters

private ArrayList<PowerFilter> filters

Defines the spectral filters to be used

fft

private FFT fft

Performs FFT

filterFunc

public double[] filterFunc

For diagnostic purposes

Constructor Detail

Fluctuation

public Fluctuation(int length,
                   double dt)

Method Detail

addFilter

public void addFilter(PowerFilter filter)

removeFilters

public void removeFilters()

newRandomDist

public void newRandomDist()

Creates new random distribution of a normalized amplitude

newSpectrum

public void newSpectrum()

Creates a new spectrum from the time series

filter

public void filter()

Applies the defined filter functions to the spectrum

inverse

public void inverse()

Obtain a new time series from the spectrum by means of an inverse FFT

newSeries

public void newSeries()

Does all the steps in a single go

getTimeSeries

public double[][] getTimeSeries()

Retrieve the time series, which has been obtained by an inverse FFT

Returns:

array with in index 0 the time and in index 1 the real amplitudes.