gsl_sf_clausen.h 1.4 KB

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  1. /* specfunc/gsl_sf_clausen.h
  2. *
  3. * Copyright (C) 1996, 1997, 1998, 1999, 2000 Gerard Jungman
  4. *
  5. * This program is free software; you can redistribute it and/or modify
  6. * it under the terms of the GNU General Public License as published by
  7. * the Free Software Foundation; either version 3 of the License, or (at
  8. * your option) any later version.
  9. *
  10. * This program is distributed in the hope that it will be useful, but
  11. * WITHOUT ANY WARRANTY; without even the implied warranty of
  12. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13. * General Public License for more details.
  14. *
  15. * You should have received a copy of the GNU General Public License
  16. * along with this program; if not, write to the Free Software
  17. * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18. */
  19. /* Author: G. Jungman */
  20. #ifndef __GSL_SF_CLAUSEN_H__
  21. #define __GSL_SF_CLAUSEN_H__
  22. #include "gsl_sf_result.h"
  23. #undef __BEGIN_DECLS
  24. #undef __END_DECLS
  25. #ifdef __cplusplus
  26. # define __BEGIN_DECLS extern "C" {
  27. # define __END_DECLS }
  28. #else
  29. # define __BEGIN_DECLS /* empty */
  30. # define __END_DECLS /* empty */
  31. #endif
  32. __BEGIN_DECLS
  33. /* Calculate the Clausen integral:
  34. * Cl_2(x) := Integrate[-Log[2 Sin[t/2]], {t,0,x}]
  35. *
  36. * Relation to dilogarithm:
  37. * Cl_2(theta) = Im[ Li_2(e^(i theta)) ]
  38. */
  39. int gsl_sf_clausen_e(double x, gsl_sf_result * result);
  40. double gsl_sf_clausen(const double x);
  41. __END_DECLS
  42. #endif /* __GSL_SF_CLAUSEN_H__ */