de.gsi.math.spectra.lomb

Class LombPeriodogram

java.lang.Object

de.gsi.math.spectra.lomb.LombPeriodogram

public class LombPeriodogram
extends Object

Class implements the computation of 'Lomb' periodograms. These allow to assess the spectral amplitudes of unequally spaced data (e.g. data sets with gaps or that consists of bursts of data) references: P. Vanicek, "Approximate Spectral Analysis by Least-Squares Fit", Astrophysics and Space Science 4 (1969) 387–391. N. R. Lomb, "Least-Squares Frequency Analysis of Unequally Spaced Data", in: Astrophysics and Space Science, Vol. 39, 1976, pp. 447–462. V. F. Pisarenko, "The retrieval of harmonics from a covariance function Geophysics", in: Royal Astronomical Society, Vol. 33, 1973, pp. 347–366.

Author:

rstein

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	DEBUG
protected int	START_THREADS

Constructor Summary

Constructors

Constructor and Description
LombPeriodogram()

Method Summary

Modifier and Type	Method and Description
double[]	computeFrequencyRange(double[] time) Compute the optimal frequency and binning range based on the acquisition range (t_max-t_min) and the minimum non-zero sampling distance.
double[]	computePeridodogram(double[] t, double[] val) Lomb periodogram computation.
double[]	computePeridodogram(double[] t, double[] val, double[] testFrequencies) Lomb periodogram computation

Methods inherited from class java.lang.Object

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

Field Detail

START_THREADS

protected int START_THREADS

DEBUG

protected boolean DEBUG

Constructor Detail

LombPeriodogram

public LombPeriodogram()

Method Detail

computeFrequencyRange

public double[] computeFrequencyRange(double[] time)

Compute the optimal frequency and binning range based on the acquisition range (t_max-t_min) and the minimum non-zero sampling distance.

Parameters:

time - time base vector

Returns:

vector containing frequency range

computePeridodogram

public double[] computePeridodogram(double[] t,
                                    double[] val)

Lomb periodogram computation. The maximum frequency and binning is derived from the acquisition range (t_max-t_min) and the minimum non-zero sampling distance.

Parameters:

t - the time indices

val - the measurement

Returns:

vector containing Lomb-type Periodogram

computePeridodogram

public double[] computePeridodogram(double[] t,
                                    double[] val,
                                    double[] testFrequencies)

Lomb periodogram computation

Parameters:

t - the time indices

val - the measurement

testFrequencies - array containing the frequencies for which the spectra is being evaluated

Returns:

vector containing Lomb-type Periodogram