File content as of revision 0:97b158e017b8:

/**
 * Demo program for BiQuad and BiQuadChain classes
 * author: T.J.W. Lankhorst <t.j.w.lankhorst@student.utwente.nl>
 */

#include <stdlib.h>
#include <iostream>
#include <iomanip>
#include <complex>
#include "BiQuad.h"

// Example: 3th order Butterworth LP (w_c = 0.1*f_nyquist)
BiQuadChain bqc;

BiQuad bq1( 9.20511e-02, -1.84501e-01, 9.24506e-02, -1.99997e+00, 9.99976e-01 );
BiQuad bq2( 1.00000e+00, -2.00367e+00, 1.00368e+00, -1.99998e+00, 9.99983e-01 );

bqc.add( &bq1 ).add( &bq2 );
int main()
{

    bqc = bq1 * bq2;

    // Find the poles of the filter
    std::cout << "Filter poles" << std::endl;
    std::vector< std::complex<double> > poles = bqc.poles();
    for( size_t i = 0; i < poles.size(); i++ )
        std::cout << "\t"  << poles[i] << std::endl;

    // Find the zeros of the filter
    std::cout << "Filter zeros" << std::endl;
    std::vector< std::complex<double> > zeros = bqc.zeros();
    for( size_t i = 0; i < poles.size(); i++ )
        std::cout << "\t" << zeros[i] << std::endl;

    // Is the filter stable?
    std::cout << "This filter is " << (bqc.stable() ? "stable" : "instable") << std::endl;

    // Output the step-response of 20 samples
    std::cout << "Step response 20 samples" << std::endl;
    for( int i = 0; i < 20; i++ )
        std::cout << "\t" << bqc.step( 1.0 ) << std::endl;

    // Done0
    return EXIT_SUCCESS;

}