public void TestFirstSamples()
{
// Act
var first = _signal.First(3);
// Assert
Assert.That(first.Samples, Is.EqualTo(new float[] { 0, 1, 2 }));
}
public static void ApplyFftToSignal(string filePath)
{
Console.WriteLine($"Applying FFT to {filePath} file");
using (var afr = new FileStream(filePath, FileMode.Open))
{
// create a signal file
var waveFile = new WaveFile(afr, false);
DiscreteSignal signal = waveFile[Channels.Left];
float[] real = signal.First(1024).Samples;
float[] imag = new float[1024];
var fft = new Fft(1024);
fft.Direct(real, imag); // in-place FFT
Console.WriteLine($"FFT size: {fft.Size}");
}
}
private void generateSignalButton_Click(object sender, EventArgs e)
{
var sampleCount = int.Parse(durationTextBox.Text);
var samplingRate = _signal1?.SamplingRate ?? 16000;
SignalBuilder signalBuilder;
switch (builderComboBox.Text)
{
case "Sinusoid":
signalBuilder = new SineBuilder();
_signal2 = signalBuilder
.SetParameter("low", -0.4f)
.SetParameter("high", 0.4f)
.SetParameter("freq", 233 /*Hz*/)
.OfLength(sampleCount)
.SampledAt(samplingRate)
.Build();
break;
case "Sawtooth":
signalBuilder = new SawtoothBuilder();
_signal2 = signalBuilder
.SetParameter("low", -0.3f)
.SetParameter("high", 0.3f)
.SetParameter("freq", 233 /*Hz*/)
.OfLength(sampleCount)
.SampledAt(samplingRate)
.Build();
break;
case "Triangle Wave":
signalBuilder = new TriangleWaveBuilder();
_signal2 = signalBuilder
.SetParameter("low", -0.3f)
.SetParameter("high", 0.3f)
.SetParameter("freq", 233 /*Hz*/)
.OfLength(sampleCount)
.SampledAt(samplingRate)
.Build();
break;
case "Square Wave":
signalBuilder = new SquareWaveBuilder();
_signal2 = signalBuilder
.SetParameter("low", -0.25f)
.SetParameter("high", 0.25f)
.SetParameter("freq", 233 /*Hz*/)
.OfLength(sampleCount)
.SampledAt(samplingRate)
.Build();
break;
case "Pulse Wave":
signalBuilder = new PulseWaveBuilder();
_signal2 = signalBuilder
.SetParameter("min", 0)
.SetParameter("max", 0.5f)
.SetParameter("pulse", 0.007f /*sec*/)
.SetParameter("period", 0.020f /*sec*/)
.OfLength(sampleCount)
.DelayedBy(50)
.SampledAt(samplingRate)
.Build();
break;
case "Chirp":
signalBuilder = new ChirpBuilder();
_signal2 = signalBuilder
.SetParameter("min", -0.3f)
.SetParameter("max", 0.3f)
.OfLength(sampleCount)
.RepeatedTimes(3)
.SampledAt(samplingRate)
.Build();
break;
case "Sinc":
signalBuilder = new SincBuilder();
_signal2 = signalBuilder
.SetParameter("min", 0)
.SetParameter("max", 0.5f)
.SetParameter("freq", 700 /*Hz*/)
.OfLength(sampleCount)
.SampledAt(samplingRate)
.Build();
break;
case "Ramp":
signalBuilder = new RampBuilder();
_signal2 = signalBuilder
.SetParameter("slope", 0.0007f)
.SetParameter("intercept", -0.5f)
.OfLength(sampleCount)
.SampledAt(samplingRate)
.Build();
break;
case "AWGN":
signalBuilder = new AwgnBuilder();
_signal2 = signalBuilder
.SetParameter("sigma", 0.25f)
.OfLength(sampleCount)
.SampledAt(samplingRate)
.Build();
break;
case "Pink Noise":
signalBuilder = new PinkNoiseBuilder();
_signal2 = signalBuilder
.SetParameter("min", -0.5f)
.SetParameter("max", 0.5f)
.OfLength(sampleCount)
.SampledAt(samplingRate)
.Build();
break;
case "Red Noise":
signalBuilder = new RedNoiseBuilder();
_signal2 = signalBuilder
.SetParameter("min", -0.5f)
.SetParameter("max", 0.5f)
.OfLength(sampleCount)
.SampledAt(samplingRate)
.Build();
break;
case "Perlin Noise":
signalBuilder = new PerlinNoiseBuilder();
_signal2 = signalBuilder
.SetParameter("min", -0.3f)
.SetParameter("max", 0.7f)
.OfLength(sampleCount)
.SampledAt(samplingRate)
.Build();
break;
default:
signalBuilder = new WhiteNoiseBuilder();
_signal2 = signalBuilder
.SetParameter("min", -0.5f)
.SetParameter("max", 0.5f)
.OfLength(sampleCount)
.SampledAt(samplingRate)
.Build();
break;
}
builderParametersListBox.Items.Clear();
builderParametersListBox.Items.AddRange(signalBuilder.GetParametersInfo());
builderParametersListBox.Items.Add("");
builderParametersListBox.Items.Add($"min: {_signal2.Samples.Min():F2}");
builderParametersListBox.Items.Add($"max: {_signal2.Samples.Max():F2}");
builderParametersListBox.Items.Add($"avg: {_signal2.Samples.Average():F4}");
if (_signal1 != null)
{
//_signal3 = _signal1 + _signal2;
var positions = Enumerable.Range(0, 3).Select(pos => pos * (_signal2.Length + 2000)).ToArray();
_signal3 = _signal1.SuperimposeMany(_signal2, positions);
superimposedSignalPanel.Signal = _signal3;
}
generatedSignalPanel.Stride = 1;
generatedSignalPanel.Signal = _signal2;
var spectrum = _fft.PowerSpectrum(_signal2.First(512));
spectrumPanel.Line = spectrum.Samples;
spectrumPanel.ToDecibel();
}
