public void PlotInvFFT(List <float> dataList, int sampleRate)
{
var windowsize = dataList.Count();
var d = Sampling.FFTFilter(dataList, windowsize, sampleRate, 5, 500);
var point = d.Select((v, index) =>
new DataPoint((double)index, v)
).ToList();
_lineSeries.Points.Clear();
_lineSeries.Points.AddRange(point);
}
public void UpdateFFTPlot(List <float> dataList, int sampleRate)
{
var windowsize = dataList.Count();
var c = Sampling.HammingFFT(dataList, windowsize);
//var c = Sampling.TestPlot(dataList, windowsize, sampleRate, 5, 500);
var s = windowsize * (1.0 / sampleRate);
var point = c.Take(c.Count() / 1).Select((v, index) =>
new DataPoint((double)index / s,
Math.Sqrt(v.Real * v.Real + v.Imaginary * v.Imaginary))
).ToList();
_lineSeries.Points.Clear();
_lineSeries.Points.AddRange(point);
_pv.InvalidatePlot(true);
}
private void TestPlot()
{
List <float> _3Hz = new List <float>();
List <float> _10Hz = new List <float>();
RecordButton.Enabled = false;
var angle = 360.0;
//sound rate is 8000 but take data is 1024
var testRate = 1024;
var c = angle / testRate;
var hz3 = c * 3;
var hz10 = c * 10;
var hz400 = c * 400;
for (int i = 0; i < testRate; i++)
{
var hz3v = (float)Math.Sin(hz3
* i * (Math.PI / 180));
var hz10v = (float)Math.Sin(hz10 *
i * (Math.PI / 180));
var hz400v = (float)Math.Sin(hz400 *
i * (Math.PI / 180));
_3Hz.Add(hz3v);
_10Hz.Add(hz10v);
//sum wave
_recorded1.Add(hz3v + hz10v);
//_recorded1.Add(hz400v);
}
_p1.UpdatePlot(_recorded1); //3HZ + 10HZ
//before FFT, Hamming.
_p2.UpdateFFTPlot(_recorded1, testRate);
//lowPassFilter = 0 HighPassFilter = 5
var f = Sampling.FFTFilter(_recorded1,
_recorded1.Count(), testRate, 0, 5);
_p3.UpdatePlot(f);
}
