dspl/low2low_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 low2low(double* b, double* a, int ord, double w0, double w1,

                     double* beta, double* alpha)

{


    double num[2] = {0.0, 1.0};

    double den[2] = {0.0, 0.0};


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

        return ERROR_PTR;

    if(ord < 1)

        return ERROR_FILTER_ORD;

    if(w0 <= 0.0 || w1 <= 0.0)

        return ERROR_FILTER_FT;


    den[0] = w1 / w0;


    return ratcompos(b, a, ord, num, den, 1, beta, alpha);

}