public static void LinearSmoothing(double[] input, double width, int fs, int fftSize, double[] output)
{
var boundary = (int)(width * fftSize / fs) + 1;
// These parameters are set by the other function.
var mirroringSpectrum = new double[fftSize / 2 + boundary * 2 + 1];
var mirroringSegment = new double[fftSize / 2 + boundary * 2 + 1];
var frequencyAxis = new double[fftSize / 2 + 1];
SetParametersForLinearSmoothing(boundary, fftSize, fs, width, input, mirroringSpectrum, mirroringSegment, frequencyAxis);
var lowLevels = new double[fftSize / 2 + 1];
var highLevels = new double[fftSize / 2 + 1];
var originOfMirroringAxis = -(boundary - 0.5) * fs / fftSize;
var discreteFrequencyInterval = (double)fs / fftSize;
MatlabFunctions.Interp1Q(originOfMirroringAxis, discreteFrequencyInterval, mirroringSegment.SubSequence(0, fftSize / 2 + boundary * 2 + 1), frequencyAxis.SubSequence(0, fftSize / 2 + 1), lowLevels);
for (int i = 0, limit = fftSize / 2; i <= limit; i++)
{
frequencyAxis[i] += width;
}
MatlabFunctions.Interp1Q(originOfMirroringAxis, discreteFrequencyInterval, mirroringSegment.SubSequence(0, fftSize / 2 + boundary * 2 + 1), frequencyAxis.SubSequence(0, fftSize / 2 + 1), highLevels);
for (int i = 0, limit = fftSize / 2; i <= limit; i++)
{
output[i] = (highLevels[i] - lowLevels[i]) / width;
}
}
public static void DCCorrection(double[] input, double f0, int fs, int fftSize, double[] output)
{
var upperLimit = 2 + (int)(f0 * fftSize / fs);
var lowFrequencyReplica = new double[upperLimit];
var lowFrequencyAxis = Enumerable.Range(0, upperLimit).Select((i) => (double)i * fs / fftSize).ToArray();
var upperLimitReplica = upperLimit - 1;
MatlabFunctions.Interp1Q(f0 - lowFrequencyAxis[0], -(double)fs / fftSize, input.SubSequence(0, upperLimit + 1), lowFrequencyAxis.SubSequence(0, upperLimitReplica), lowFrequencyReplica);
for (var i = 0; i < upperLimitReplica; i++)
{
output[i] = input[i] + lowFrequencyReplica[i];
}
}
