dspl/ratcompos_8c_source.html

/*

* Copyright (c) 2015-2024 Sergey Bakhurin

* Digital Signal Processing Library [http://dsplib.org]

*

* This file is part of libdspl-2.0.

*

* is free software: you can redistribute it and/or modify

* it under the terms of the GNU Lesser    General Public License as published by

* the Free Software Foundation, either version 3 of the License, or

* (at your option) any later version.

*

* DSPL 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 Lesser General Public License

* along with Foobar.    If not, see <http://www.gnu.org/licenses/>.

*/


#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include "dspl.h"


#ifdef DOXYGEN_ENGLISH


#endif

#ifdef DOXYGEN_RUSSIAN


#endif

int DSPL_API ratcompos(double* b, double* a, int n,

                       double* c, double* d, int p,

                       double* beta, double* alpha)

{


    int k2, i, k,    pn, pd, ln, ld, k2s, nk2s;

    double *num = NULL, *den = NULL, *ndn = NULL, *ndd = NULL;

    int res;


    if (!a || !b || !c || !d || !beta || !alpha)

    {

        res = ERROR_PTR;

        goto exit_label;

    }

    if(n < 1 || p < 1)

    {

        res =    ERROR_SIZE;

        goto exit_label;

    }


    k2   = (n*p)+1;

    k2s  = k2*sizeof(double);     /* alpha and beta size */

    nk2s = (n+1)*k2*sizeof(double); /* num, den, ndn and ndd size */


    num = (double*)malloc(nk2s);

    den = (double*)malloc(nk2s);

    ndn = (double*)malloc(nk2s);

    ndd = (double*)malloc(nk2s);


    memset(num, 0, nk2s);

    memset(den, 0, nk2s);

    memset(ndn, 0, nk2s);

    memset(ndd, 0, nk2s);


    num[0] = den[0] = 1.0;

    pn = 0;

    ln = 1;

    for(i = 1; i < n+1; i++)

    {

        res = conv(num+pn, ln, c, p+1, num+pn+k2);

        if(res!=RES_OK)

            goto exit_label;

        res = conv(den+pn, ln, d, p+1, den+pn+k2);

        if(res!=RES_OK)

            goto exit_label;

        pn += k2;

        ln += p;

    }


    pn = 0;

    pd = n*k2;

    ln = 1;

    ld = k2;


    for (i = 0; i < n+1; i++)

    {

        res = conv(num + pn, ln, den + pd, ld, ndn + i*k2);

        if(res!=RES_OK)

            goto exit_label;

        ln += p;

        ld -= p;

        pn += k2;

        pd -= k2;

    }


    for (i = 0; i < n+1; i++)

    {

        for (k = 0; k < k2; k++)

        {

            ndd[i*k2 + k] = ndn[i*k2 + k] * a[i];

            ndn[i*k2 + k] *= b[i];

        }

    }


    memset(alpha, 0, k2s);

    memset(beta,  0, k2s);


    for (k = 0; k < k2; k++)

    {

        for (i = 0; i < n+1; i++)

        {

            beta[k]  += ndn[i*k2 + k];

            alpha[k] += ndd[i*k2 + k];

        }

    }


    res = RES_OK;


exit_label:

    if(num)

        free(num);

    if(den)

        free(den);

    if(ndn)

        free(ndn);

    if(ndd)

        free(ndd);


    return res;

}