filter_plot.cpp

Output

Source

 
#include "sigpack.h"
 
using namespace arma;
using namespace sp;
 
int main()
{
    gplot gp;
    gp.window( "Filter plots", 10, 10, 700, 700 );
 
    vec Mg( 1024 );
    vec Ph( 1024 );
    vec a, b;
    a  = { 1 };
    b  = fir1( 44, 0.25 );
    Mg = 20 * log10( freqz( b, a, 1024 ) );
    Ph = phasez( b, a, 1024 );
 
    // Plot
    gp.set_term( "qt" );
    gp.grid_on();
    gp.send2gp( "set multiplot layout 2, 1" );
    gp.send2gp( "set xtics (\"0\" 1,\"0.5\" 512,\"1\" 1024)" ); // Direct call to
                                                                // gnuplot pipe
    gp.ylabel( "Magnitude [dB]" );
    gp.xlabel( "Frequency [f/Fs]" );
    gp.plot_add( Mg, "Filter" );
    gp.plot_show();
    gp.send2gp( "set xtics (\"0\" 1,\"0.5\" 512,\"1\" 1024)" ); // Direct call to
                                                                // gnuplot pipe
    gp.ylabel( "Phase [rad]" );
    gp.xlabel( "Frequency [f/Fs]" );
    gp.plot_add( Ph, "Filter" );
    gp.plot_show();
    gp.send2gp( "unset multiplot" );
 
    return 0;
}