Package de.gsi.math.spectra.lomb

Class LombPeriodogram

  • public class LombPeriodogram
extends java.lang.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 Description
      protected boolean DEBUG  
      protected int START_THREADS  

    • Constructor Summary

      Constructors 
      Constructor Description
      LombPeriodogram()  

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method 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