example1b.c

Ejemplo de uso del Filtro Iir con cero en -1 y polo en 0.9, para una señal sinusoidal con frecuencia (angular) en pi/32, 3*pi/4, y una componente constante igual 1.

Autor

Fernando Pujaico Rivera

Fecha

21-05-2011
Test de un filtro IIR.

El filtro usado será:

Señal de entrada x[n].

Señal de salida y[n].

/*
 * example1b.c
 * 
 * Copyright 2011 Fernando Pujaico Rivera <fernando.pujaico.rivera@gmail.com>
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301, USA.
 * 
 */


#include <config.h>
#include <stdlib.h>
#include <pds/pdsdf.h>
#include <pds/pdsvector.h>
#include "extras.h"
#include <math.h>

int main(int argc, char** argv)
{
    PdsIir *IIR1=NULL;
    PdsVector *hden=NULL;
    PdsVector *hnum=NULL;
    PdsDfReal x,y;
    PdsDfNatural n,N;
    FILE *fd=NULL;
    char DATAFILE[]="datos.txt";
    char OCTAVEFILE[]="plotinoctave.m";
    PdsVector *X=NULL;
    PdsVector *Y1=NULL;
    PdsVector *Y2=NULL;


    //-------------------------- Creando filtro IIR --------------------------//

    // hnum=[ 1/20 1/20] 
    PdsRaReal num[]={1/20.0,1/20.0};
    hnum=pds_vector_new_array1d(num,2);

    // hden=[1.0 -0.9]
    PdsRaReal den[]={1.0   ,-0.9  };
    hden=pds_vector_new_array1d(den,2);

    IIR1=pds_iir_new(hnum,hden);
    //------------------------------------------------------------------------//


    N=128;
    X=pds_vector_new(N);
    Y1=pds_vector_new(N);


    for(n=0;n<N;n++)
    {
        x=1.0+sin(M_PI*n/32.0)+sin(3.0*M_PI*n/4.0+M_PI/16.0);
        pds_iir_evaluate_value(IIR1,x,&y);

        X->V[n]=x;
        Y1->V[n]=y;
    }
    pds_iir_free(IIR1);

    Y2=pds_vector_new(N);
    IIR1=pds_iir_new(hnum,hden);
    pds_iir_evaluate_vector(IIR1,X,Y2);
    pds_iir_free(IIR1);

    fd=fopen(DATAFILE,"w");
    if(fd==NULL)    return EXIT_FAILURE;
    pds_vector_fprintf(X,fd);
    pds_vector_fprintf(Y1,fd);
    pds_vector_fprintf(Y2,fd);
    fclose(fd);

    pds_octave_plot_lin(OCTAVEFILE,DATAFILE);

    pds_vector_free(hnum);    
    pds_vector_free(hden);    
    return EXIT_SUCCESS;
}