Setting default FFT window to Hanning

src/AnalysisPrograms/Create4Sonograms.cs

@@ -112,7 +112,7 @@ public static void Main(Arguments arguments)
 
             var recording = new AudioRecording(fiOutputSegment.FullName);
 
-            // EXTRACT ENVELOPE and SPECTROGRAM
+            // EXTRACT ENVELOPE and SPECTROGRAM// This call uses the default FFT window.
             var dspOutput = DSP_Frames.ExtractEnvelopeAndFfts(recording, frameSize, windowOverlap);
 
             // average absolute value over the minute recording

src/AnalysisPrograms/SnrAnalysis.cs

@@ -114,6 +114,7 @@ public static void Execute(Arguments arguments)
             int frameCount = signalLength / stepSize;
 
             // (B) ################################## EXTRACT ENVELOPE and SPECTROGRAM ##################################
+            // Calling this method will set the default FFT window.
             var dspOutput = DSP_Frames.ExtractEnvelopeAndFfts(
                 recording,
                 sonoConfig.WindowSize,

src/AudioAnalysisTools/DSP/DSP_Frames.cs

@@ -133,22 +133,31 @@ public static int FrameStep(int windowSize, double windowOverlap)
             return frames;
         }
 
+        /// <summary>
+        /// Calling this method will set default FFT window if windowName is null.
+        /// Otherwise sets the FFT window specified in the config file.
+        /// </summary>
         public static EnvelopeAndFft ExtractEnvelopeAndFfts(AudioRecording recording, int frameSize, double overlap, string windowName = null)
         {
             int frameStep = (int)(frameSize * (1 - overlap));
             return ExtractEnvelopeAndAmplSpectrogram(recording.WavReader.Samples, recording.SampleRate, recording.Epsilon, frameSize, frameStep, windowName);
         }
 
+        /// <summary>
+        /// Calling this method sets the default FFT window, currently HANNING - see FFT.cs line 22.
+        /// </summary>
         public static EnvelopeAndFft ExtractEnvelopeAndFfts(AudioRecording recording, int frameSize, int frameStep)
         {
-            string windowName = FFT.KeyHammingWindow;
-            return ExtractEnvelopeAndAmplSpectrogram(recording.WavReader.Samples, recording.SampleRate, recording.Epsilon, frameSize, frameStep, windowName);
+            return ExtractEnvelopeAndAmplSpectrogram(recording.WavReader.Samples, recording.SampleRate, recording.Epsilon, frameSize, frameStep, FFT.DefaultFftWindow);
         }
 
+        /// <summary>
+        /// Calling this method sets the default FFT window, currently HANNING - see FFT.cs line 22.
+        /// </summary>
         public static EnvelopeAndFft ExtractEnvelopeAndAmplSpectrogram(double[] signal, int sampleRate, double epsilon, int frameSize, double overlap)
         {
             int frameStep = (int)(frameSize * (1 - overlap));
-            return ExtractEnvelopeAndAmplSpectrogram(signal, sampleRate, epsilon, frameSize, frameStep, FFT.KeyHammingWindow);
+            return ExtractEnvelopeAndAmplSpectrogram(signal, sampleRate, epsilon, frameSize, frameStep, FFT.DefaultFftWindow);
         }
 
         /// <summary>
@@ -196,7 +205,7 @@ public static EnvelopeAndFft ExtractEnvelopeAndAmplSpectrogram(
             // set up the FFT parameters
             if (windowName == null)
             {
-                windowName = FFT.KeyHammingWindow;
+                windowName = FFT.DefaultFftWindow;
             }
 
             FFT.WindowFunc w = FFT.GetWindowFunction(windowName);

src/TowseyLibrary/FFT.cs

@@ -19,6 +19,7 @@ public sealed class FFT
         public const string KeyNoWindow = "NONE";
         public const string KeyHammingWindow = "HAMMING";
         public const string KeyHanningWindow = "HANNING";
+        public const string DefaultFftWindow = KeyHanningWindow;
 
         public delegate double WindowFunc(int n, int N);
 
@@ -338,9 +339,13 @@ private static double lrw(double a0, double a1, double a2, double a3, int n, int
             return 1.0 - (1.93 * c1) + (1.29 * c2) - (0.388 * c3) + (0.032 * c4);
         };
 
+        /// <summary>
+        /// Returns an FFT window function given the name of the window type.
+        /// </summary>
+        /// <param name="name">FFT window name.</param>
+        /// <returns>FFT.WindowFunc.</returns>
         public static WindowFunc GetWindowFunction(string name)
         {
-            //FFT.WindowFunc windowFnc;
             if (name.StartsWith(KeyHammingWindow))
             {
                 return Hamming;

tests/Acoustics.Test/AudioAnalysisTools/EventStatistics/EventStatisticsCalculateTests.cs

@@ -59,9 +59,9 @@ public void TestCalculateEventStatistics()
             LoggedConsole.WriteLine($"Stats: DominantFrequency= {stats.DominantFrequency}");
 
             Assert.AreEqual(0.0, stats.TemporalEnergyDistribution, 1E-4);
-            Assert.AreEqual(0.6062, stats.SpectralEnergyDistribution, 1E-4);
-            Assert.AreEqual(6687, stats.SpectralCentroid);
-            Assert.AreEqual(8003, stats.DominantFrequency);
+            Assert.AreEqual(0.61647, stats.SpectralEnergyDistribution, 1E-4);
+            Assert.AreEqual(6011, stats.SpectralCentroid);
+            Assert.AreEqual(3998, stats.DominantFrequency);
 
             Assert.AreEqual(1500, stats.LowFrequencyHertz);
             Assert.AreEqual(8500, stats.HighFrequencyHertz);

tests/Acoustics.Test/AudioAnalysisTools/Indices/ClusterIndexTest.cs

@@ -73,10 +73,10 @@ public void TestBinaryClusteringOfSpectra()
             var clusterSpectrum = SpectralClustering.RestoreFullLengthSpectrum(clusterInfo.ClusterSpectrum, freqBinCount, lowerBinBound);
 
             // test the cluster count - also called spectral diversity in some papers
-            Assert.AreEqual(clusterInfo.ClusterCount, 17);
+            Assert.AreEqual(clusterInfo.ClusterCount, 19);
 
             // test the trigram count - another way of thinking about spectral change
-            Assert.AreEqual(clusterInfo.TriGramUniqueCount, 342);
+            Assert.AreEqual(clusterInfo.TriGramUniqueCount, 436);
 
             // test what used to be the CLS spectral index. Sum of the rows of the weight vectors.
             var expectedSpectrumFile = PathHelper.ResolveAsset("BinaryClustering", "clusterSpectrum.bin");

tests/Acoustics.Test/AudioAnalysisTools/Indices/IndexCalculateTest.cs

@@ -79,27 +79,27 @@ public void TestOfSummaryIndices()
 
             var summaryIndices = results.SummaryIndexValues;
 
-            Assert.AreEqual(0.6793287, summaryIndices.AcousticComplexity, AllowedDelta);
+            Assert.AreEqual(0.689085, summaryIndices.AcousticComplexity, AllowedDelta);
             Assert.AreEqual(0.484520, summaryIndices.Activity, AllowedDelta);
             Assert.AreEqual(-30.946519, summaryIndices.AvgSignalAmplitude, AllowedDelta);
             Assert.AreEqual(11.533420, summaryIndices.AvgSnrOfActiveFrames, AllowedDelta);
             Assert.AreEqual(-39.740775, summaryIndices.BackgroundNoise, AllowedDelta);
-            Assert.AreEqual(21, summaryIndices.ClusterCount);
-            Assert.AreEqual(0.153191, summaryIndices.EntropyOfAverageSpectrum, AllowedDelta);
-            Assert.AreEqual(0.301929, summaryIndices.EntropyOfCoVSpectrum, AllowedDelta);
-            Assert.AreEqual(0.260999, summaryIndices.EntropyOfPeaksSpectrum, AllowedDelta);
-            Assert.AreEqual(0.522080, summaryIndices.EntropyOfVarianceSpectrum, AllowedDelta);
+            Assert.AreEqual(23, summaryIndices.ClusterCount);
+            Assert.AreEqual(0.153642, summaryIndices.EntropyOfAverageSpectrum, AllowedDelta);
+            Assert.AreEqual(0.299602, summaryIndices.EntropyOfCoVSpectrum, AllowedDelta);
+            Assert.AreEqual(0.264981, summaryIndices.EntropyOfPeaksSpectrum, AllowedDelta);
+            Assert.AreEqual(0.522530, summaryIndices.EntropyOfVarianceSpectrum, AllowedDelta);
             Assert.AreEqual(2.0, summaryIndices.EventsPerSecond, AllowedDelta);
-            Assert.AreEqual(0.467151, summaryIndices.SpectralCentroid, AllowedDelta);
-            Assert.AreEqual(0.140306, summaryIndices.HighFreqCover, AllowedDelta);
-            Assert.AreEqual(0.137873, summaryIndices.MidFreqCover, AllowedDelta);
-            Assert.AreEqual(0.055341, summaryIndices.LowFreqCover, AllowedDelta);
-            Assert.AreEqual(0.957433, summaryIndices.Ndsi, AllowedDelta);
+            Assert.AreEqual(0.462917, summaryIndices.SpectralCentroid, AllowedDelta);
+            Assert.AreEqual(0.148697, summaryIndices.HighFreqCover, AllowedDelta);
+            Assert.AreEqual(0.139938, summaryIndices.MidFreqCover, AllowedDelta);
+            Assert.AreEqual(0.048843, summaryIndices.LowFreqCover, AllowedDelta);
+            Assert.AreEqual(0.957532, summaryIndices.Ndsi, AllowedDelta);
             Assert.AreEqual(27.877206, summaryIndices.Snr, AllowedDelta);
-            Assert.AreEqual(6.240310, summaryIndices.SptDensity, AllowedDelta);
+            Assert.AreEqual(6.257752, summaryIndices.SptDensity, AllowedDelta);
             Assert.AreEqual(0, summaryIndices.ResultStartSeconds);
             Assert.AreEqual(0.162216, summaryIndices.TemporalEntropy, AllowedDelta);
-            Assert.AreEqual(401, summaryIndices.ThreeGramCount, AllowedDelta);
+            Assert.AreEqual(487, summaryIndices.ThreeGramCount, AllowedDelta);
         }
 
         /// <summary>
@@ -139,7 +139,7 @@ public void TestOfSpectralIndices()
             // 1:ACI
             var expectedSpectrumFile = PathHelper.ResolveAsset("Indices", "ACI.bin");
 
-            //Binary.Serialize(expectedSpectrumFile, spectralIndices.ACI);
+            // Binary.Serialize(expectedSpectrumFile, spectralIndices.ACI);
             var expectedVector = Binary.Deserialize<double[]>(expectedSpectrumFile);
             CollectionAssert.That.AreEqual(expectedVector, spectralIndices.ACI, AllowedDelta);
 
@@ -174,7 +174,7 @@ public void TestOfSpectralIndices()
             // 6:OSC
             expectedSpectrumFile = PathHelper.ResolveAsset("Indices", "OSC.bin");
 
-            //Binary.Serialize(expectedSpectrumFile, spectralIndices.OSC);
+            // Binary.Serialize(expectedSpectrumFile, spectralIndices.OSC);
             expectedVector = Binary.Deserialize<double[]>(expectedSpectrumFile);
             CollectionAssert.That.AreEqual(expectedVector, spectralIndices.OSC, AllowedDelta);
 
@@ -263,13 +263,13 @@ public void TestOfSpectralIndices_ICD20()
             var resourcesDir = PathHelper.ResolveAssetPath("Indices");
             var expectedSpectrumFile = PathHelper.ResolveAsset("Indices", "BGN_ICD20.bin");
 
-            //Binary.Serialize(expectedSpectrumFile, spectralIndices.BGN);
+            // Binary.Serialize(expectedSpectrumFile, spectralIndices.BGN);
             var expectedVector = Binary.Deserialize<double[]>(expectedSpectrumFile);
             CollectionAssert.That.AreEqual(expectedVector, spectralIndices.BGN, AllowedDelta);
 
             expectedSpectrumFile = PathHelper.ResolveAsset("Indices", "CVR_ICD20.bin");
 
-            //Binary.Serialize(expectedSpectrumFile, spectralIndices.CVR);
+            // Binary.Serialize(expectedSpectrumFile, spectralIndices.CVR);
             expectedVector = Binary.Deserialize<double[]>(expectedSpectrumFile);
             CollectionAssert.That.AreEqual(expectedVector, spectralIndices.CVR, AllowedDelta);
 
@@ -333,12 +333,16 @@ public void TestOfSpectralIndices_Octave()
             // TEST the BGN SPECTRAL INDEX
             Assert.AreEqual(256, spectralIndices.BGN.Length);
 
-            //Binary.Serialize(expectedSpectrumFile, spectralIndices.BGN);
-            var expectedVector = Binary.Deserialize<double[]>(PathHelper.ResolveAsset("Indices", "BGN_OctaveScale.bin"));
+            var expectedSpectrumFile1 = PathHelper.ResolveAsset("Indices", "BGN_OctaveScale.bin");
+
+            // Binary.Serialize(expectedSpectrumFile1, spectralIndices.BGN);
+            var expectedVector = Binary.Deserialize<double[]>(expectedSpectrumFile1);
             CollectionAssert.That.AreEqual(expectedVector, spectralIndices.BGN, AllowedDelta);
 
-            //Binary.Serialize(expectedSpectrumFile, spectralIndices.CVR);
-            expectedVector = Binary.Deserialize<double[]>(PathHelper.ResolveAsset("Indices", "CVR_OctaveScale.bin"));
+            var expectedSpectrumFile2 = PathHelper.ResolveAsset("Indices", "CVR_OctaveScale.bin");
+
+            // Binary.Serialize(expectedSpectrumFile2, spectralIndices.CVR);
+            expectedVector = Binary.Deserialize<double[]>(expectedSpectrumFile2);
             CollectionAssert.That.AreEqual(expectedVector, spectralIndices.CVR, AllowedDelta);
         }
     }

tests/Acoustics.Test/AudioAnalysisTools/Oscillations2014/OscillationTests.cs

@@ -85,18 +85,13 @@ public void TwoOscillationTests()
                 // construct name of expected matrix osc spectrogram to save file
                 var expectedMatrixFile = PathHelper.ResolveAsset("Oscillations2014", stem + ".Matrix.EXPECTED.csv");
 
-                // SAVE THE OUTPUT if true
+                // SAVE THE image of oscillation spectrogram if true.
                 // WARNING: this will overwrite fixtures
                 if (false)
                 {
-                    // 1: save image of oscillation spectrogram
                     string imageName = stem + ".EXPECTED.png";
                     string imagePath = Path.Combine(PathHelper.ResolveAssetPath("Oscillations2014"), imageName);
                     tuple.Item1.Save(imagePath);
-
-                    // 2: Save matrix of oscillation data stored in freqOscilMatrix1
-                    //Csv.WriteMatrixToCsv(expectedMatrixFile, tuple.Item2);
-                    Binary.Serialize(expectedMatrixFile, tuple.Item2);
                 }
 
                 // Run two tests. Have to deserialise the expected data files
@@ -105,6 +100,8 @@ public void TwoOscillationTests()
                 Assert.AreEqual(675, tuple.Item1.Height);
 
                 // 2. Compare matrix data
+                //    Save matrix in expectedMatrixFile
+                // Binary.Serialize(expectedMatrixFile, tuple.Item2);
                 var expectedMatrix = Binary.Deserialize<double[,]>(expectedMatrixFile);
 
                 //TODO  Following test fails when using CSV reader because the reader cuts out first line of the matrix
@@ -132,35 +129,31 @@ public void SpectralIndexOsc_Test()
                 var threshold = Oscillations2014.DefaultSensitivityThreshold;
                 var spectralIndex = Oscillations2014.GetSpectralIndex_Osc(recordingSegment, frameLength, sampleLength, threshold);
 
-                // 3. construct name of spectral index vector
-                // SAVE THE OUTPUT if true
+                // 3. construct name of spectral index vector and save as image file
+                // No need to do tests on this image but it is useful to visualise output
                 // WARNING: this will overwrite fixtures
                 var sourceName = Path.GetFileNameWithoutExtension(sourceRecording.Name);
-                var stem = sourceName + ".SpectralIndex.OSC";
-                var expectedIndexPath = PathHelper.ResolveAsset("Oscillations2014", stem + ".EXPECTED.csv");
                 if (false)
                 {
-                    // 4. Save spectral index vector to file
-                    //Csv.WriteToCsv(expectedIndexPath, spectralIndex);
-                    //Json.Serialise(expectedIndexPath, spectralIndex);
-                    Binary.Serialize(expectedIndexPath, spectralIndex);
-
-                    // 5. Get the vector as image and save as image file
-                    // no need to do tests on this image but it is useful to visualise output
                     var expectedVectorImage = ImageTools.DrawVectorInColour(DataTools.reverseArray(spectralIndex), cellWidth: 10);
-                    var expectedImagePath = PathHelper.ResolveAsset("Oscillations2014", stem + ".png");
+                    var expectedImagePath = PathHelper.ResolveAsset("Oscillations2014", sourceName + ".SpectralIndex.OSC.png");
                     expectedVectorImage.Save(expectedImagePath.FullName);
                 }
 
                 // 6. Get the vector as image and save as image file
                 // no need to do tests on this image but it is useful to compare with expected visual output
                 var currentVectorImage = ImageTools.DrawVectorInColour(DataTools.reverseArray(spectralIndex), cellWidth: 10);
-                var currentImagePath = Path.Combine(this.outputDirectory.FullName, stem + ".png");
+                var currentImagePath = Path.Combine(this.outputDirectory.FullName, sourceName + ".SpectralIndex.OSC.png");
                 currentVectorImage.Save(currentImagePath);
 
                 // 7. Run test. Compare vectors
                 // TODO  this test fails when using CSV reader because the reader cuts out first element/line of the vector
                 //var expectedVector = (double[])Csv.ReadFromCsv<double>(expectedIndexPath);
+                var expectedIndexPath = PathHelper.ResolveAsset("Oscillations2014", sourceName + ".SpectralIndex.OSC.EXPECTED.csv");
+
+                //comment the following line once fixture is saved.
+                // Binary.Serialize(expectedIndexPath, spectralIndex);
+
                 var expectedVector = Binary.Deserialize<double[]>(expectedIndexPath);
                 CollectionAssert.That.AreEqual(expectedVector, spectralIndex, 0.000001);
             }