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DFTandSpectralWindow improvement #598

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Merged
dbenn merged 1 commit into from
May 8, 2026
Merged

DFTandSpectralWindow improvement #598

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113 changes: 55 additions & 58 deletions plugin/src/org/aavso/tools/vstar/external/plugin/DFTandSpectralWindow.java
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Original file line number Diff line number Diff line change
Expand Up @@ -18,10 +18,12 @@
package org.aavso.tools.vstar.external.plugin;

import java.awt.BorderLayout;
import java.awt.Button;
import java.awt.Color;
import java.awt.Component;
import java.awt.Cursor;
import java.awt.Desktop;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
Expand All @@ -38,6 +40,8 @@
import java.util.concurrent.CountDownLatch;

import javax.swing.BorderFactory;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.ButtonGroup;
import javax.swing.JButton;
import javax.swing.JComboBox;
Expand Down Expand Up @@ -1178,7 +1182,8 @@ private boolean parametersDialog() throws AlgorithmError {
new RunParametersDialog(
minFrequency,
maxFrequency,
resolution,
resolution,
ftResult != null ? ftResult.getObservationTimeSpan() : 0.0,
analysisType,
harmonicCount);

Expand Down Expand Up @@ -1206,19 +1211,22 @@ private class RunParametersDialog implements Runnable {
private double minFrequency;
private double maxFrequency;
private double resolution;
private double timeSpan;
private FAnalysisType analysisType;
private int harmonicCount;
private boolean dialogCancelled;

public RunParametersDialog(
double minFrequency,
double maxFrequency,
double resolution,
double resolution,
double timeSpan,
FAnalysisType analysisType,
int harmonicCount) {
this.minFrequency = minFrequency;
this.maxFrequency = maxFrequency;
this.resolution = resolution;
this.timeSpan = timeSpan;
this.analysisType = analysisType;
this.harmonicCount = harmonicCount;
}
Expand All @@ -1236,6 +1244,12 @@ public void run() {
DoubleField resolutionField = new DoubleField("Resolution", 0.0, null, resolution);
fields.add(resolutionField);

JPanel addPanel = new JPanel();
addPanel.setLayout(new BoxLayout(addPanel, BoxLayout.PAGE_AXIS));
Button defaultResolution = new Button("Recommended Resolution");
addPanel.add(defaultResolution);
addPanel.add(Box.createRigidArea(new Dimension(75, 20)));

JPanel analysisTypePane = new JPanel();
analysisTypePane.setLayout(new GridLayout(0, 3));
analysisTypePane.setBorder(BorderFactory.createTitledBorder("Analysis Type"));
Expand Down Expand Up @@ -1300,6 +1314,18 @@ public void run() {
else
harmonicSelector.setSelectedIndex(0);

defaultResolution.addActionListener(e-> {
if (timeSpan > 0) {
int harmonicCount = mhdftRadioButton.isSelected() ? harmonicSelector.getSelectedIndex() + 1 : 1;
double resolution = 0.05 / timeSpan / harmonicCount;
resolutionField.setValue(resolution);
}
else
MessageBox.showErrorDialog("Error", "Cannot get recommended resolution");
});

addPanel.add(analysisTypePane);

while (true) {
boolean legalParams = true;

Expand All @@ -1308,7 +1334,7 @@ public void run() {
"Parameters",
getDocName(),
fields,
Optional.of(analysisTypePane));
Optional.of(addPanel));

dialogCancelled = dlg.isCancelled();
if (dialogCancelled)
Expand Down Expand Up @@ -1424,6 +1450,7 @@ public static class FtResult {
private double maxTime;
private double minTime;
private double meanTime;
private double timeSpan;
private double meanMag;
private double varpMag;
private double varpTime;
Expand All @@ -1448,6 +1475,7 @@ public FtResult(List<ValidObservation> obs) {
minTime = 0.0;
maxTime = 0.0;
meanTime = 0.0;
timeSpan = 0.0;
meanMag = 0.0;
boolean first = true;
for (int i = 0; i < count; i++) {
Expand All @@ -1473,7 +1501,9 @@ public FtResult(List<ValidObservation> obs) {
varpTime = calcPopVariance(times);
medianTimeInterval = calcMedianTimeInterval(times);

zeroFrequencyCut = 0.95 / Math.sqrt(12.0 * varpTime) / 4.0;
timeSpan = maxTime - minTime;

zeroFrequencyCut = 0.95 / Math.sqrt(12.0 * varpTime) / 4.0; // From Foster
}

public static double calcPopVariance(double d[]) {
Expand Down Expand Up @@ -1525,77 +1555,43 @@ public double[] calculateF(double nu) {
if (analysisType == FAnalysisType.DFT || analysisType == FAnalysisType.SPW) {
boolean typeIsDFT = analysisType != FAnalysisType.SPW;
for (int i = 0; i < count; i++) {
double a = omega * times[i];
double a = omega * (times[i] - meanTime);
double b = typeIsDFT ? mags[i] - meanMag : 0.5;
//reF += b * Math.cos(a);
//imF += b * Math.sin(a);
// Faster than Math.sin, Math.cos
double tanAd2 = Math.tan(a / 2.0);
double tanAd2squared = tanAd2 * tanAd2;
reF += b * ((1 - tanAd2squared) / (1 + tanAd2squared));
imF += b * (2.0 * tanAd2 / (1 + tanAd2squared));
reF += b * Math.cos(a);
imF += b * Math.sin(a);
}
// Like Period04
amp = 2.0 * Math.sqrt(reF * reF + imF * imF) / count;
pwr = amp * amp;
// } else if (analysisType == FAnalysisType.DCDFT) {
// // Use the zero-frequency cut, like in Foster's code, to suppress the huge amplitude peak at zero.
// if (nu < zeroFrequencyCut) {
// amp = Double.NaN;
// pwr = Double.NaN;
// } else {
// double[] a = new double[times.length];
// double[][] cos_sin = new double[times.length][2];
// for (int i = 0; i < times.length; i++) {
// a[i] = omega * times[i];
// //cos_sin[i][0] = Math.cos(a[i]);
// //cos_sin[i][1] = Math.sin(a[i]);
// double tanAd2 = Math.tan(a[i] / 2.0);
// double tanAd2squared = tanAd2 * tanAd2;
// cos_sin[i][0] = (1 - tanAd2squared) / (1 + tanAd2squared);
// cos_sin[i][1] = (2.0 * tanAd2 / (1 + tanAd2squared));
// }
//
// OLSMultipleLinearRegression regression = new OLSMultipleLinearRegression();
// regression.newSampleData(mags, cos_sin);
//
// double[] beta = regression.estimateRegressionParameters();
// double b1 = beta[1];
// double b2 = beta[2];
// double[] predicted_mags = new double[times.length]; // excluding mag zero level, not needed
// for (int i = 0; i < times.length; i++) {
// predicted_mags[i] = b1 * cos_sin[i][0] + b2 * cos_sin[i][1];
// }
// amp = Math.sqrt(b1 * b1 + b2 * b2);
// pwr = calcPopVariance(predicted_mags) * (times.length - 1) / varpMag / 2.0;
// }
} else {
int localHarmonicCount;
double localZeroFrequencyCut;
if (analysisType == FAnalysisType.DCDFT) {
localHarmonicCount = 1;
localZeroFrequencyCut = zeroFrequencyCut;
} else {
localHarmonicCount = harmonicCount;
localZeroFrequencyCut = zeroFrequencyCut * localHarmonicCount;
}
// Use the zero-frequency cut, like in Foster's code, to suppress the huge amplitude peak at zero.
if (nu < zeroFrequencyCut) {
if (nu < localZeroFrequencyCut) {
amp = Double.NaN;
pwr = Double.NaN;
} else {
int localHarmonicCount = harmonicCount;
if (analysisType == FAnalysisType.DCDFT)
localHarmonicCount = 1;
double[] a = new double[times.length];
double[][] cos_sin = new double[times.length][2 * localHarmonicCount];
for (int i = 0; i < times.length; i++) {
a[i] = omega * times[i];
a[i] = omega * (times[i] - meanTime);
for (int n = 0; n < localHarmonicCount; n++) {
//cos_sin[i][2 * n] = Math.cos((n + 1) * a[i]);
//cos_sin[i][2 * n + 1] = Math.sin((n + 1) * a[i]);
double tanAd2 = Math.tan((n + 1) * a[i] / 2.0);
double tanAd2squared = tanAd2 * tanAd2;
cos_sin[i][2 * n] = (1 - tanAd2squared) / (1 + tanAd2squared);
cos_sin[i][2 * n + 1] = (2.0 * tanAd2 / (1 + tanAd2squared));
cos_sin[i][2 * n] = Math.cos((n + 1) * a[i]);
cos_sin[i][2 * n + 1] = Math.sin((n + 1) * a[i]);
}
}

OLSMultipleLinearRegression regression = new OLSMultipleLinearRegression();
OLSMultipleLinearRegression regression = new OLSMultipleLinearRegression();
regression.newSampleData(mags, cos_sin);

double[] beta = regression.estimateRegressionParameters();

double[] predicted_mags = new double[times.length]; // excluding mag zero level, not needed
for (int i = 0; i < times.length; i++) {
predicted_mags[i] = 0.0;
Expand Down Expand Up @@ -1626,7 +1622,7 @@ public double getMedianTimeInterval() {
}

public double getObservationTimeSpan() {
return maxTime - minTime;
return timeSpan;
}

public double getObservationMeanTime() {
Expand Down Expand Up @@ -1687,7 +1683,8 @@ else if (a.d < b.d)
}
}

class LinkLabel extends JLabel {
@SuppressWarnings("serial")
class LinkLabel extends JLabel {

public LinkLabel(String text, String urlString) {
super(text);
Expand Down
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