cerf.h /size: 4805 b    last modification: 2025-02-21 11:03
1/* Library libcerf:
2 *   Compute complex error functions, based on a new implementation of
3 *   Faddeeva's w_of_z. Also provide Dawson and Voigt functions.
4 *
5 * File cerf.h:
6 *   Declare exported functions.
7 *
8 * Copyright:
9 *   (C) 2012 Massachusetts Institute of Technology
10 *   (C) 2013 Forschungszentrum Jülich GmbH
11 *
12 * Licence:
13 *   Permission is hereby granted, free of charge, to any person obtaining
14 *   a copy of this software and associated documentation files (the
15 *   "Software"), to deal in the Software without restriction, including
16 *   without limitation the rights to use, copy, modify, merge, publish,
17 *   distribute, sublicense, and/or sell copies of the Software, and to
18 *   permit persons to whom the Software is furnished to do so, subject to
19 *   the following conditions:
20 *
21 *   The above copyright notice and this permission notice shall be
22 *   included in all copies or substantial portions of the Software.
23 *
24 *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25 *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26 *   MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27 *   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
28 *   LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
29 *   OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
30 *   WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
31 *
32 * Authors:
33 *   Steven G. Johnson, Massachusetts Institute of Technology, 2012, core author
34 *   Joachim Wuttke, Forschungszentrum Jülich, 2013, package maintainer
35 *
36 * Website:
37 *   http://apps.jcns.fz-juelich.de/libcerf
38 *
39 * Revision history:
40 *   ../CHANGELOG
41 *
42 * Man pages:
43 *   w_of_z(3), dawson(3), voigt(3), cerf(3), erfcx(3), erfi(3)
44 */
45
46 /*
47
48    This file is patched by Mojca Miklavec and Hans Hagen for usage in LuaMetaTeX where we use
49    only C and also want to compile with the Microsoft compiler. So, when updating this library
50    one has to check for changes. Not that we expect many as this is a rather stable library.
51
52    In the other files there are a few macros used that deal with the multiplication and addition
53    of complex and real numbers. Of course the original code is kept as-is.
54
55 */
56
57# ifndef __CERF_H
58#   define __CERF_H
59
60# include <complex.h>
61
62# if (_MSC_VER)
63    # define _cerf_cmplx _Dcomplex
64# else
65    typedef double _Complex _cerf_cmplx;
66# endif
67
68# define EXPORT
69
70extern _cerf_cmplx w_of_z                (_cerf_cmplx z);                          /* compute w(z) = exp(-z^2) erfc(-iz), Faddeeva's scaled complex error function */
71extern double      im_w_of_x             (double x);                               /* special case Im[w(x)] of real x */
72extern double      re_w_of_z             (double x, double y);                     
73extern double      im_w_of_z             (double x, double y);                     
74                                                                                   
75extern _cerf_cmplx cerf                  (_cerf_cmplx z);                          /* compute erf(z), the error function of complex arguments */
76extern _cerf_cmplx cerfc                 (_cerf_cmplx z);                          /* compute erfc(z) = 1 - erf(z), the complementary error function */
77                                                                                   
78extern _cerf_cmplx cerfcx                (_cerf_cmplx z);                          /* compute erfcx(z) = exp(z^2) erfc(z), an underflow-compensated version of erfc */
79extern double      erfcx                 (double x);                               /* special case for real x */
80                                                                                   
81extern _cerf_cmplx cerfi                 (_cerf_cmplx z);                          /* compute erfi(z) = -i erf(iz), the imaginary error function */
82extern double      erfi                  (double x);                               /* special case for real x */
83                                                                                   
84extern _cerf_cmplx cdawson               (_cerf_cmplx z);                          /* compute dawson(z) = sqrt(pi)/2 * exp(-z^2) * erfi(z), Dawson's integral */
85extern double      dawson                (double x);                               /* special case for real x */
86
87extern double      voigt                 (double x, double sigma, double gamma);   /* compute voigt(x,...), the convolution of a Gaussian and a Lorentzian */
88extern double      voigt_hwhm            (double sigma, double gamma, int *error); /* compute the full width at half maximum of the Voigt function */
89
90extern double      cerf_experimental_imw (double x, double y);
91extern double      cerf_experimental_rew (double x, double y);
92
93#endif
94