using System;

using System.Collections.Generic;

using System.Text;

namespace Spectrogram

{

public static class SignalGenerator

{

public static float[] NoisySin(

double durationSeconds = 1,

int sampleRateHz = 8000,

double signalFrequencyHz = 2000,

double noiseLevel = .1

)

{

int pointCount = (int)(durationSeconds * sampleRateHz);

float[] values = new float[pointCount];

// create a sine wave

float oscillations = (float)(signalFrequencyHz * durationSeconds);

for (int i = 0; i < values.Length; i++)

values[i] = (float)Math.Sin(((float)i / values.Length) * 2 * Math.PI * oscillations);

// add noise

Random rand = new Random();

for (int i = 0; i < values.Length; i++)

values[i] += (float)((rand.NextDouble() - .5) * noiseLevel);

return values;

}

}

}