kopia lustrzana https://github.com/Dsplib/libdspl-2.0
307 wiersze
6.9 KiB
C
307 wiersze
6.9 KiB
C
/*
|
|
* Copyright (c) 2015-2019 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"
|
|
|
|
|
|
/******************************************************************************
|
|
* Recalculate ws frequency to 1 rad/s for HPF and BANDSTOP filters
|
|
******************************************************************************/
|
|
double DSPL_API filter_ws1(int ord, double rp, double rs, int type)
|
|
{
|
|
double es2, ep2, gs2, x, ws;
|
|
|
|
if(ord<1 || rp < 0.0 || rs < 0.0)
|
|
return -1.0;
|
|
|
|
es2 = pow(10.0, rs*0.1) - 1.0;
|
|
ep2 = pow(10.0, rp*0.1) - 1.0;
|
|
gs2 = 1.0 / (1.0 + es2);
|
|
|
|
x = (1.0 - gs2) / (gs2 * ep2);
|
|
|
|
switch( type & DSPL_FILTER_APPROX_MASK)
|
|
{
|
|
case DSPL_FILTER_BUTTER:
|
|
ws = pow(x, 0.5 / (double)ord);
|
|
break;
|
|
case DSPL_FILTER_CHEBY1:
|
|
case DSPL_FILTER_CHEBY2:
|
|
x = sqrt(x) + sqrt(x - 1.0);
|
|
x = log(x) / (double)ord;
|
|
ws = 0.5 * (exp(-x) + exp(x));
|
|
break;
|
|
case DSPL_FILTER_ELLIP:
|
|
{
|
|
double k, k1;
|
|
complex_t y, z;
|
|
int res;
|
|
k = sqrt(ep2 / es2);
|
|
res = ellip_modulareq(rp, rs, ord, &k1);
|
|
if(res != RES_OK)
|
|
{
|
|
ws = -1.0;
|
|
break;
|
|
}
|
|
RE(z) = sqrt(x);
|
|
IM(z) = 0.0;
|
|
|
|
res = ellip_acd_cmplx(&z, 1, k, &y);
|
|
if(res != RES_OK)
|
|
{
|
|
ws = -1.0;
|
|
break;
|
|
}
|
|
RE(y) /= (double)ord;
|
|
IM(y) /= (double)ord;
|
|
res = ellip_cd_cmplx(&y, 1, k1, &z);
|
|
if(res != RES_OK)
|
|
{
|
|
ws = -1.0;
|
|
break;
|
|
}
|
|
ws = RE(z);
|
|
break;
|
|
}
|
|
default:
|
|
ws = -1.0;
|
|
break;
|
|
}
|
|
return ws;
|
|
}
|
|
|
|
/******************************************************************************
|
|
* low 2 bandpass transformation
|
|
******************************************************************************/
|
|
int DSPL_API low2bp(double* b, double* a, int ord,
|
|
double w0, double wpl, double wph,
|
|
double* beta, double* alpha)
|
|
{
|
|
|
|
double num[3] = {0.0, 0.0, 1.0};
|
|
double den[3] = {0.0, 0.0, 0.0};
|
|
|
|
if(!b || !a || !beta || !alpha)
|
|
return ERROR_PTR;
|
|
if(ord < 1)
|
|
return ERROR_FILTER_ORD;
|
|
if(w0 <= 0.0 || wpl <= 0.0 || wph <= 0.0 || wph <= wpl)
|
|
return ERROR_FILTER_FT;
|
|
|
|
num[0] = (wph * wpl) / (w0 * w0);
|
|
den[1] = (wph - wpl) / w0;
|
|
|
|
return ratcompos(b, a, ord, num, den, 2, beta, alpha);
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/******************************************************************************
|
|
* low 2 bandstop transformation
|
|
******************************************************************************/
|
|
int DSPL_API low2bs(double* b, double* a, int ord,
|
|
double w0, double wsl, double wsh,
|
|
double* beta, double* alpha)
|
|
{
|
|
|
|
double den[3] = {0.0, 0.0, 1.0};
|
|
double num[3] = {0.0, 0.0, 0.0};
|
|
|
|
if(!b || !a || !beta || !alpha)
|
|
return ERROR_PTR;
|
|
if(ord < 1)
|
|
return ERROR_FILTER_ORD;
|
|
if(w0 <= 0.0 || wsl <= 0.0 || wsh <= 0.0 || wsh <= wsl)
|
|
return ERROR_FILTER_FT;
|
|
|
|
den[0] = (wsh * wsl) / (w0 * w0);
|
|
num[1] = (wsh - wsl) / w0;
|
|
|
|
return ratcompos(b, a, ord, num, den, 2, beta, alpha);
|
|
}
|
|
|
|
|
|
|
|
|
|
/******************************************************************************
|
|
* low 2 high transformation
|
|
******************************************************************************/
|
|
int DSPL_API low2high(double* b, double* a, int ord, double w0, double w1,
|
|
double* beta, double* alpha)
|
|
{
|
|
|
|
double num[2] = {0.0, 0.0};
|
|
double den[2] = {0.0, 1.0};
|
|
|
|
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;
|
|
|
|
num[0] = w1 / w0;
|
|
|
|
return ratcompos(b, a, ord, num, den, 1, beta, alpha);
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
/******************************************************************************
|
|
low 2 low transformation
|
|
*******************************************************************************/
|
|
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);
|
|
}
|
|
|
|
|
|
|
|
|
|
/******************************************************************************
|
|
Rational composition
|
|
*******************************************************************************/
|
|
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;
|
|
}
|
|
|