libdspl-2.0/dspl/src/complex.c

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C

/*
* Copyright (c) 2015-2019 Sergey Bakhurin
* Digital Signal Processing Library [http://dsplib.org]
*
* This file is part of DSPL.
*
* 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 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 General Public License
* along with Foobar. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdio.h>
#include <stdlib.h>
#include "dspl.h"
/******************************************************************************
\ingroup SPEC_MATH_TRIG_GROUP
\fn int acos_cmplx(complex_t* x, int n, complex_t *y)
\brief The inverse of the cosine function the complex vector argument `x`
Function calculates the inverse of the cosine function as:<BR>
\f[
\textrm{Arccos}(x) = \frac{\pi}{2} - \textrm{Arcsin}(x) =
\frac{\pi}{2} -j \textrm{Ln}\left( j x + \sqrt{1 - x^2} \right)
\f]
\param[in] x Pointer to the argument vector `x`.<BR>
Vector size is `[n x 1]`. <BR><BR>
\param[in] n Input vector `x` and the inverse cosine vector `y` size.<BR><BR>
\param[out] y Pointer to the output complex vector `y`,
corresponds to the input vector `x`.<BR>
Vector size is `[n x 1]`. <BR>
Memory must be allocated. <BR><BR>
\return
`RES_OK` if function calculated successfully. <BR>
Else \ref ERROR_CODE_GROUP "code error".<BR>
Example:<BR>
\code{.cpp}
complex_t x[3] = {{1.0, 2.0}, {3.0, 4.0}, {5.0, 6.0}};
complex_t y[3];
int k;
acos_cmplx(x, 3, y);
for(k = 0; k < 3; k++)
printf("acos_cmplx(%.1f%+.1fj) = %.3f%+.3fj\n",
RE(x[k]), IM(x[k]), RE(y[k]), IM(y[k]));
\endcode
<BR>
Output is:<BR>
\verbatim
acos_cmplx(1.0+2.0j) = 1.144-1.529j
acos_cmplx(3.0+4.0j) = 0.937-2.306j
acos_cmplx(5.0+6.0j) = 0.880-2.749j
\endverbatim
\author
Sergey Bakhurin www.dsplib.org
*******************************************************************************/
int DSPL_API acos_cmplx(complex_t* x, int n, complex_t *y)
{
int k, res;
double pi2 = 0.5 * M_PI;
res = asin_cmplx(x, n, y);
if(res != RES_OK)
return res;
for(k = 0; k < n; k++)
{
RE(y[k]) = pi2 - RE(y[k]);
IM(y[k]) = - IM(y[k]);
}
return RES_OK;
}
/******************************************************************************
\ingroup SPEC_MATH_TRIG_GROUP
\fn int asin_cmplx(complex_t* x, int n, complex_t *y)
\brief The inverse of the sine function the complex vector argument `x`
Function calculates the inverse of the sine function as:<BR>
\f[
\textrm{Arcsin}(x) = j \textrm{Ln}\left( j x + \sqrt{1 - x^2} \right)
\f]
\param[in] x Pointer to the argument vector `x`.<BR>
Vector size is `[n x 1]`. <BR><BR>
\param[in] n Input vector `x` and the inverse sine vector `y` size.<BR><BR>
\param[out] y Pointer to the output complex vector `y`,
corresponds to the input vector `x`.<BR>
Vector size is `[n x 1]`. <BR>
Memory must be allocated. <BR><BR>
\return
`RES_OK` if function calculated successfully. <BR>
Else \ref ERROR_CODE_GROUP "code error".<BR>
Example:<BR>
\code{.cpp}
complex_t x[3] = {{1.0, 2.0}, {3.0, 4.0}, {5.0, 6.0}};
complex_t y[3];
int k;
asin_cmplx(x, 3, y);
for(k = 0; k < 3; k++)
printf("asin_cmplx(%.1f%+.1fj) = %.3f%+.3fj\n",
RE(x[k]), IM(x[k]), RE(y[k]), IM(y[k]));
\endcode
<BR>
Output is:<BR>
\verbatim
asin_cmplx(1.0+2.0j) = 0.427+1.529j
asin_cmplx(3.0+4.0j) = 0.634+2.306j
asin_cmplx(5.0+6.0j) = 0.691+2.749j
\endverbatim
\author
Sergey Bakhurin www.dsplib.org
*******************************************************************************/
int DSPL_API asin_cmplx(complex_t* x, int n, complex_t *y)
{
int k;
complex_t tmp;
if(!x || !y)
return ERROR_PTR;
if(n < 1)
return ERROR_SIZE;
for(k = 0; k < n; k++)
{
RE(tmp) = 1.0 - CMRE(x[k], x[k]); // 1-x[k]^2
IM(tmp) = - CMIM(x[k], x[k]); // 1-x[k]^2
sqrt_cmplx(&tmp, 1, y+k); // sqrt(1 - x[k]^2)
RE(y[k]) -= IM(x[k]); // j * x[k] + sqrt(1 - x[k]^2)
IM(y[k]) += RE(x[k]); // j * x[k] + sqrt(1 - x[k]^2)
log_cmplx(y+k, 1, &tmp); // log( j * x[k] + sqrt(1 - x[k]^2) )
RE(y[k]) = IM(tmp); // -j * log( j * x[k] + sqrt(1 - x[k]^2) )
IM(y[k]) = -RE(tmp); // -j * log( j * x[k] + sqrt(1 - x[k]^2) )
}
return RES_OK;
}
/******************************************************************************
\ingroup TYPES_GROUP
\fn int cmplx2re(complex_t* x, int n, double* re, double* im)
\brief Separate complex vector to the real and image vectors
Function fills `re` and `im` vectors corresponds to real and image
parts of the input complex array `x`. <BR>
\param[in] x Pointer to the real complex vector.<BR>
Vector size is `[n x 1]`. <BR><BR>
\param[in] n Size of the input complex vector `x` and real and image
vectors `re` and `im`.<BR><BR>
\param[out] re Pointer to the real part vector.<BR>
Vector size is `[n x 1]`. <BR>
Memory must be allocated. <BR><BR>
\param[out] im Pointer to the image part vector.<BR>
Vector size is `[n x 1]`. <BR>
Memory must be allocated. <BR><BR>
\return
`RES_OK` if function converts complex vector successfully. <BR>
Else \ref ERROR_CODE_GROUP "code error".<BR>
Example:<BR>
\code{.cpp}
complex_t x[3] = {{1.0, 2.0}, {3.0, 4.0}, {5.0, 6.0}};
double re[3], im[3];
cmplx2re(x, 3, re, im);
\endcode
Vectors `re` and `im` will contains:
\verbatim
re[0] = 1.0; im[0] = 2.0;
re[1] = 3.0; im[1] = 4.0;
re[2] = 5.0; im[2] = 6.0;
\endverbatim
\author Sergey Bakhurin. www.dsplib.org
*******************************************************************************/
int DSPL_API cmplx2re(complex_t* x, int n, double* re, double* im)
{
int k;
if(!x)
return ERROR_PTR;
if(n < 1)
return ERROR_SIZE;
if(re)
{
for(k = 0; k < n; k++)
re[k] = RE(x[k]);
}
if(im)
{
for(k = 0; k < n; k++)
im[k] = IM(x[k]);
}
return RES_OK;
}
/******************************************************************************
\ingroup SPEC_MATH_TRIG_GROUP
\fn int cos_cmplx(complex_t* x, int n, complex_t *y)
\brief The cosine function the complex vector argument `x`
Function calculates the cosine function as:<BR>
\f[
\textrm{cos}(x) = \frac{\exp(jx) + \exp(-jx)}{2}
\f]
\param[in] x Pointer to the argument vector `x`.<BR>
Vector size is `[n x 1]`. <BR><BR>
\param[in] n Input vector `x` and the cosine vector `y` size.<BR><BR>
\param[out] y Pointer to the output complex vector `y`,
corresponds to the input vector `x`.<BR>
Vector size is `[n x 1]`. <BR>
Memory must be allocated. <BR><BR>
\return
`RES_OK` if function calculated successfully. <BR>
Else \ref ERROR_CODE_GROUP "code error".<BR>
Example:<BR>
\code{.cpp}
complex_t x[3] = {{1.0, 2.0}, {3.0, 4.0}, {5.0, 6.0}};
complex_t y[3];
int k;
cos_cmplx(x, 3, y);
for(k = 0; k < 3; k++)
printf("cos_cmplx(%.1f%+.1fj) = %9.3f%+9.3fj\n",
RE(x[k]), IM(x[k]), RE(y[k]), IM(y[k]));
\endcode
<BR>
Output is:<BR>
\verbatim
cos_cmplx(1.0+2.0j) = 2.033 -3.052j
cos_cmplx(3.0+4.0j) = -27.035 -3.851j
cos_cmplx(5.0+6.0j) = 57.219 +193.428j
\endverbatim
\author
Sergey Bakhurin www.dsplib.org
*******************************************************************************/
int DSPL_API cos_cmplx(complex_t* x, int n, complex_t *y)
{
int k;
double ep, em, sx, cx;
if(!x || !y)
return ERROR_PTR;
if(n < 1)
return ERROR_SIZE;
for(k = 0; k < n; k++)
{
ep = exp( IM(x[k]));
em = exp(-IM(x[k]));
sx = 0.5 * sin(RE(x[k]));
cx = 0.5 * cos(RE(x[k]));
RE(y[k]) = cx * (em + ep);
IM(y[k]) = sx * (em - ep);
}
return RES_OK;
}
/******************************************************************************
Logarithm complex
*******************************************************************************/
int DSPL_API log_cmplx(complex_t* x, int n, complex_t *y)
{
int k;
if(!x || !y)
return ERROR_PTR;
if(n < 1)
return ERROR_SIZE;
for(k = 0; k < n; k++)
{
RE(y[k]) = 0.5 * log(ABSSQR(x[k]));
IM(y[k]) = atan2(IM(x[k]), RE(x[k]));
}
return RES_OK;
}
/******************************************************************************
convert double array to a complex array
*******************************************************************************/
int DSPL_API re2cmplx(double* x, int n, complex_t* y)
{
int k;
if(!x || !y)
return ERROR_PTR;
if(n < 1)
return ERROR_SIZE;
for(k = 0; k < n; k++)
{
RE(y[k]) = x[k];
IM(y[k]) = 0.0;
}
return RES_OK;
}
/******************************************************************************
Complex cosine
*******************************************************************************/
int DSPL_API sin_cmplx(complex_t* x, int n, complex_t *y)
{
int k;
double ep, em, sx, cx;
if(!x || !y)
return ERROR_PTR;
if(n < 1)
return ERROR_SIZE;
for(k = 0; k < n; k++)
{
ep = exp( IM(x[k]));
em = exp(-IM(x[k]));
sx = 0.5 * sin(RE(x[k]));
cx = 0.5 * cos(RE(x[k]));
RE(y[k]) = sx * (em + ep);
IM(y[k]) = cx * (ep - em);
}
return RES_OK;
}
/******************************************************************************
SQRT complex
*******************************************************************************/
int DSPL_API sqrt_cmplx(complex_t* x, int n, complex_t *y)
{
int k;
double r, zr;
complex_t t;
if(!x || !y)
return ERROR_PTR;
if(n < 1)
return ERROR_SIZE;
for(k = 0; k < n; k++)
{
r = ABS(x[k]);
RE(t) = RE(x[k]) + r;
IM(t) = IM(x[k]);
zr = 1.0 / ABS(t);
r = sqrt(r);
RE(y[k]) = RE(t) * zr * r;
IM(y[k]) = IM(t) * zr * r;
}
return RES_OK;
}