Koen Pepping

Waveform periods

 

For a school assignment I had to write a program that outputs the data for a single sine wave period.

I used Gnuplot to plot the data, and I added the option to output Sawtooth, square and triangle just because i thought it was educational. 

 

 

#define NUM_OF_PERIODS 2 // sets the number of periods 

#define NUM_OF_HARMONICS 250 // sets the number of harmonics for the sawtooth 

 

int F = 480;

int SR = 48000;

int length = (SR / (F/NUM_OF_PERIODS));

float amp = 1;

double y;

int x;

 

Sinewave:

 

for(x = 0; x <= length; x++)

{

       double fundamental = (sin(x*2*M_PI*F/SR));  

       y = fundamental;

 

       cout << x << "\t" << y << endl;

}

 

Sawtooth:

 

for(x = 0; x <= length; x++)

{

     double fundamental = (sin(x*2*M_PI*F/SR)); // fundamental sine

     for(int i = 2; i <= NUM_OF_HARMONICS; i++)

     {

         fundamental = (fundamental + ((amp/i)*(sin(x*2*M_PI*(F*i)/SR)))); //adds harmonics to the fundamental sinewave

        y = fundamental;

     }

  cout << x << "\t" << y << endl; 

}

 

Squarewave:

 

for(x = 0; x <= length; x++)

{

     double fundamental = (sin(x*2*M_PI*F/SR)); // fundamental sine

 

     for(int i = 3; i <= 79; i += 2) // + 2 for odd harmonics only 

     {

         fundamental = (fundamental + ((amp/i)*(sin(x*2*M_PI*(F*i)/SR)))); //adds odd harmonics to the fundamental sinewave

         y = fundamental;

     }

   cout << x << "\t" << y << endl; 

}

 

Trianglewave:

 

for(x = 0; x <= length; x++)

{

       double fundamental = (sin(x*2*M_PI*F/SR)); // fundamental sine

       int t = -1;

 

       for(int i = 3; i <= 127; i += 2)

       {

            fundamental = fundamental + ( (pow(t,(i /2))*(amp/pow(i, 2)))*(sin(x*2*M_PI*(F*i)/SR))); 

            //adds odd harmonics with amplitude 1/(harmonic^2) to the fundamental sinewave,

           

           y = fundamental;

        }

cout << x << "\t" << y << endl;

}