Package org.opensourcephysics.analysis

Class FourierAnalysis

java.lang.Object
org.opensourcephysics.analysis.FourierAnalysis
All Implemented Interfaces:
Data
public class FourierAnalysis extends Object implements Data
FourierAnalysis adds gutter points to complex-number data before performing a fast Fourier transform. Gutter points increase the number points in order to approximate a nonperiodic function. The FFT output is phase shifted to account for the fact that the FFT basis functions are defined on [0, 2*pi].
Version:
1.0
Author:
W. Christian

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected int
    datasetID
     

  • Constructor Summary

    Constructors
    Constructor
    Description
    FourierAnalysis()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    double[]
    doAnalysis(double[] x, double[] z, int gutter)
    Fourier analyzes the given complex data z[] after adding gutter points at the start and end of the z[] array.
    String[]
    getColumnNames()
    The column names to be used in the data display tool
    double[][]
    getData2D()
    Gets the frequencies, real, and imaginary coefficients.
    double[][][]
    getData3D()
    3D data is not available.
    List<Data>
    getDataList()
    Gets a list that contains the complex dataset of the last Fourier analysis.
    ArrayList<Dataset>
    getDatasets()
    Gets the complex datasets that contain the result of the last Fourier analysis.
    Color[]
    getFillColors()
    Fill colors for Data interface.
    int
    getID()
    Returns a unique identifier for this Data.
    Color[]
    getLineColors()
    Line colors for Data interface.
    String
    getName()
    Gets the dataset name.
    double[]
    getNaturalFreq()
    Gets the frequencies of the Fourier spectrum.
    double[]
    getNaturalOmega()
    Gets the angular frequencies of the Fourier spectrum.
    boolean
    isRadians()
    Gets the radians flag.
    double[]
    repeatAnalysis(double[] z)
    Repeats the Fourier analysis of the complex data z[] with the previously set scale and gutter.
    void
    setID(int id)
    Sets the ID number of this Data.
    void
    setName(String name)
    Sets a name that can be used to identify the dataset.
    void
    useRadians(boolean radians)
    Sets the radians flag for the frequency values of datasets.

    Methods inherited from class java.lang.Object

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

  • Field Details

    • datasetID

      protected int datasetID

  • Constructor Details

    • FourierAnalysis

      public FourierAnalysis()

  • Method Details

    • doAnalysis

      public double[] doAnalysis(double[] x, double[] z, int gutter)
      Fourier analyzes the given complex data z[] after adding gutter points at the start and end of the z[] array.
      Parameters:
      x - double[]
      z - double[]
      gutter - int
      Returns:
      double[] the Fourier spectrum

    • repeatAnalysis

      public double[] repeatAnalysis(double[] z)
      Repeats the Fourier analysis of the complex data z[] with the previously set scale and gutter.
      Parameters:
      z - double[]
      Returns:
      double[] the Fourier spectrum

    • getNaturalOmega

      public double[] getNaturalOmega()
      Gets the angular frequencies of the Fourier spectrum.
      Returns:
      double[]

    • getNaturalFreq

      public double[] getNaturalFreq()
      Gets the frequencies of the Fourier spectrum.
      Returns:
      double[]

    • useRadians

      public void useRadians(boolean radians)
      Sets the radians flag for the frequency values of datasets. Dataset x-values are either frequencies (cycles) or angular frequencies (radians) depending on the value of the radians flag.
      Parameters:
      radians - boolean

    • isRadians

      public boolean isRadians()
      Gets the radians flag. Radians is true if the dataset uses angular frequency as the x-coordinate.
      Returns:
      boolean

    • getDataList

      public List<Data> getDataList()
      Gets a list that contains the complex dataset of the last Fourier analysis. Complex dataset x-values are either frequencies (cycles) or angular frequencies (radians) depending on the value of the radians flag.
      Specified by:
      getDataList in interface Data
      Returns:
      list of ComplexDatasets

    • getDatasets

      public ArrayList<Dataset> getDatasets()
      Gets the complex datasets that contain the result of the last Fourier analysis. Real coefficients are contained in the first dataset. Complex coefficients are in the second dataset.
      Specified by:
      getDatasets in interface Data
      Returns:
      list of Datasets

    • getData2D

      public double[][] getData2D()
      Gets the frequencies, real, and imaginary coefficients.
      Specified by:
      getData2D in interface Data
      Returns:
      double[][]

    • getData3D

      public double[][][] getData3D()
      3D data is not available.
      Specified by:
      getData3D in interface Data
      Returns:
      double[][][]

    • setName

      public void setName(String name)
      Sets a name that can be used to identify the dataset.
      Parameters:
      name - String

    • getName

      public String getName()
      Gets the dataset name.
      Specified by:
      getName in interface Data
      Returns:
      String

    • getColumnNames

      public String[] getColumnNames()
      The column names to be used in the data display tool
      Specified by:
      getColumnNames in interface Data
      Returns:

    • getLineColors

      public Color[] getLineColors()
      Line colors for Data interface.
      Specified by:
      getLineColors in interface Data
      Returns:

    • getFillColors

      public Color[] getFillColors()
      Fill colors for Data interface.
      Specified by:
      getFillColors in interface Data
      Returns:

    • setID

      public void setID(int id)
      Sets the ID number of this Data.
      Specified by:
      setID in interface Data
      Parameters:
      id - the ID number

    • getID

      public int getID()
      Returns a unique identifier for this Data.
      Specified by:
      getID in interface Data
      Returns:
      the ID number