Fixed up histogram to use magnitude, added magnitude and phase polar …

…components

SampleGenerator/Sample.cs

@@ -4,6 +4,7 @@
  * */
 using SignalGenerator;
 using SignalProcessor;
+using SignalProcessor.Filters;
 using System;
 using System.Collections.Generic;
 using System.Linq;
@@ -35,20 +36,40 @@ public Sample(int sampleRate, double seconds, double hertz, ISignalGenerator sig
             _seconds = seconds;
             _hertz = hertz;
 
-            int sampleCount = (int)Math.Ceiling(_sampleRate * _seconds);
-            int cycleCount = (int)Math.Ceiling(_seconds * _hertz);
-
+
             if (sigGen != null)
             { 
-                _samples = sigGen.GetSignal(sampleCount, cycleCount);
+                _samples = sigGen.GetSignal(SampleCount, CycleCount);
             }
             else
             {
-                _samples = new List<double>(cycleCount); // Create empty sample list
+                _samples = new List<double>(CycleCount); // Create empty sample list
             }
             _sampleIDX = 0;
         }
 
+        public int SampleRate
+        {
+            get
+            {
+                return _sampleRate;
+            }
+        }
+        public int SampleCount
+        {
+            get
+            {
+                return (int)Math.Ceiling(_sampleRate * _seconds);
+            }
+        }
+
+        public int CycleCount
+        {
+            get
+            {
+                return (int)Math.Ceiling(_seconds * _hertz);
+            }
+        }
         public FrequencyDomain GetFrequencyDomainForSlice
         {
             get
@@ -68,7 +89,7 @@ public List<Double> GetSignalSlice
         // 64 channel DFT done on 50 samples + 14 zeros padded right
         public List<double> Get50Padded64ChannelSamples()
         {
-            int numSamplesToGet = 32;
+            int numSamplesToGet = 64;
             int curIDX = _sampleIDX;
             if (curIDX + numSamplesToGet >= _samples.Count)
             {

SignalProcessor/DFT.cs

@@ -61,6 +61,23 @@ public double ScaledImaginaryComponent(int K)
 
             return (ImaginaryComponent[K] * ScalingFactor[K]);
         }
+
+
+        // See page 162, Equation 8-6 and 8-7 in "The Scientist and Engineer's Guide to Digital Signal Processing
+        #region polarcoords
+        public double Magnitude(int k)
+        {
+            return Math.Sqrt(Math.Pow(ScaledRealComponent(k), 2) + Math.Pow(ScaledImaginaryComponent(k), 2));
+        }
+
+        public double Phase(int k)
+        {
+            if (ScaledRealComponent(k) == 0)
+                return Math.PI / 2.0;
+
+            return Math.Atan(ScaledImaginaryComponent(k) / ScaledRealComponent(k));
+        }
+        #endregion
     }
 
     public class DFT

Signals And Transforms/MainWindow.xaml

@@ -44,6 +44,10 @@
                 <ComboBoxItem Name="HighPass">High</ComboBoxItem>
                 <ComboBoxItem Name="None">None</ComboBoxItem>
             </ComboBox>
+
+            <Label Margin="10,0,0,0" Content="Clip Percent:" Foreground="Black" FontWeight="Bold" VerticalAlignment="Center"/>
+            <TextBox HorizontalAlignment="Left" Height="20" Width="40" Margin="5,0,0,0" KeyUp="TextBox_KeyEnterUpdate" Text="{Binding FilterClipPercentage}" VerticalAlignment="Center"/>
+
         </StackPanel>
         <views:HistogramView VerticalAlignment="Stretch" HorizontalAlignment="Stretch" Grid.Row="1"/>
     </Grid>

Signals And Transforms/Models/SampleData.cs

@@ -31,26 +31,26 @@ public static Sample SignalSample
 
                         Sample sinusoidSamp = new Sample(16000, 1, 500, sinusoid);
                         Sample sinusoidSamp2 = new Sample(16000, 1, 7000, sinusoid);
-                        Sample whiteNoise = new Sample(16000, 1, 2000, random);
+                        Sample whiteNoise = new Sample(16000, 1, 1000, random);
                         Sample squareWave = new Sample(8000, 1, 400, square);
-                        _signalSample = sinusoidSamp.SumWithSample(sinusoidSamp2);
+                        _signalSample = sinusoidSamp.SumWithSample(whiteNoise);
                     }
 
-                    _signalSample.GetNextSamplesForTimeSlice(20); // Prime the pump
+                    _signalSample.Get50Padded64ChannelSamples(); // Prime the pump
                     return _signalSample;
                 }
             }
         }
 
-        public static void SetFilter(PASSTYPE _filterType)
+        public static void SetFilter(PASSTYPE _filterType, double clipPercent)
         {
             if (_filterType == PASSTYPE.NONE)
             {
                 _filter = null;
             }
             else
             {
-                _filter = new SimplePassFilter(0.15, _filterType);
+                _filter = new SimplePassFilter(clipPercent, _filterType);
             }
         }
 

Signals And Transforms/View Models/GraphViewModel.cs

@@ -27,7 +27,7 @@ public class GraphViewModel : INotifyPropertyChanged
         int _cycleCount;
         private string _filterType;
         int _framesPerSecond = 0;
-
+        private int _filterClipPercentage;
 
         public event PropertyChangedEventHandler PropertyChanged;
 
@@ -38,6 +38,9 @@ public GraphViewModel()
             _signalScale = 1.0;
             _filterType = "None";
             _dispatchTimer = new DispatcherTimer();
+            _signal = new List<double>(1000);
+            _synthesis = new List<double>(1000);
+
             FramesPerSecond = 10;
             GetNewModel();
 
@@ -101,25 +104,29 @@ private void GetNewModel()
             switch (_filterType)
             {
                 case "Low":
-                    SampleData.SetFilter(PASSTYPE.LOW);
+                    SampleData.SetFilter(PASSTYPE.LOW, _filterClipPercentage/100.0);
                     break;
                 case "High":
-                    SampleData.SetFilter(PASSTYPE.HIGH);
+                    SampleData.SetFilter(PASSTYPE.HIGH, _filterClipPercentage/100.0);
                     break;
                 default:
-                    SampleData.SetFilter(PASSTYPE.NONE);
+                    SampleData.SetFilter(PASSTYPE.NONE, _filterClipPercentage/100.0);
                     break;
             }
 
-            _signal = SampleData.Get50Padded64ChannelSamples();
-            _frequencyDomain = SampleData.FreqDomain;
-
-            _synthesis = DFT.Synthesize(_frequencyDomain);
+            _synthesis.Clear();
+            _signal.Clear();
+            while (_signal.Count < 1000)
+            { 
+                _signal.AddRange(SampleData.Get50Padded64ChannelSamples());
+                _frequencyDomain = SampleData.FreqDomain;
 
+                _synthesis.AddRange(DFT.Synthesize(_frequencyDomain));
+            }
 
             this.MyModel = new PlotModel { Title = "Signal And Synthesis" };
-            this.MyModel.Series.Add(new FunctionSeries(getSynthesis, 0, 1000 - 1, 1.0, "Synthesis")); // Clip synthesis to signal sample count
-            this.MyModel.Series.Add(new FunctionSeries(getSignal, 0, 1000 - 1, 1.0, "Signal"));
+            this.MyModel.Series.Add(new FunctionSeries(getSynthesis, 0, _signal.Count - 1, 1.0, "Synthesis")); // Clip synthesis to signal sample count
+           // this.MyModel.Series.Add(new FunctionSeries(getSignal, 0, _signal.Count - 1, 1.0, "Signal"));
 
             NotifyPropertyChanged("MyModel");
         }
@@ -152,6 +159,23 @@ public String FilterType
             }
         }
 
+        public int FilterClipPercentage
+        {
+            get
+            {
+                return _filterClipPercentage;
+            }
+            set
+            {
+                _filterClipPercentage = value > 0 ? value : 0;
+                if (_filterClipPercentage > 100)
+                    _filterClipPercentage = 100;
+
+                NotifyPropertyChanged();
+                GetNewModel();
+            }
+        }
+
         public int CycleCount
         {
             get

Signals And Transforms/View Models/HistogramViewModel.cs

@@ -38,7 +38,6 @@ public HistogramViewModel()
         private void GetNewModel()
         {
 
-            _signal = _signalSample.GetNextSamplesForTimeSlice(20);
             _frequencyDomain = SampleData.FreqDomain;
 
             MyModel = new PlotModel { Title = "Frequency Histogram" };
@@ -48,11 +47,12 @@ private void GetNewModel()
             var linearAxis2 = new LinearAxis();
             MyModel.Axes.Add(linearAxis2);
             var linearBarSeries1 = new LinearBarSeries();
-            linearBarSeries1.Title = "Frequency";
+            linearBarSeries1.Title = "Hertz";
 
             for (int idx = 0; idx < _frequencyDomain.RealComponent.Count; idx++)
             {
-                linearBarSeries1.Points.Add(new DataPoint(idx, _frequencyDomain.ScaledRealComponent(idx)));
+                int hz = (int)Math.Floor((0.5) * ((float)idx / (float)(_frequencyDomain.RealComponent.Count - 1)) * SampleData.SignalSample.SampleRate);
+                linearBarSeries1.Points.Add(new DataPoint(hz, _frequencyDomain.Magnitude(idx)));
             }
 
             MyModel.Series.Add(linearBarSeries1);