You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

47 lines
1.1KB

  1. /*
  2. Implementation of the Lambert W function
  3. Copyright (C) 2011 Darko Veberic, darko.veberic@ijs.si
  4. This program is free software: you can redistribute it and/or modify
  5. it under the terms of the GNU General Public License as published by
  6. the Free Software Foundation, either version 3 of the License, or
  7. (at your option) any later version.
  8. This program is distributed in the hope that it will be useful,
  9. but WITHOUT ANY WARRANTY; without even the implied warranty of
  10. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11. GNU General Public License for more details.
  12. You should have received a copy of the GNU General Public License
  13. along with this program. If not, see <http://www.gnu.org/licenses/>.
  14. */
  15. #ifndef _utl_LambertW_h_
  16. #define _utl_LambertW_h_
  17. #include <limits>
  18. namespace utl {
  19. template<int branch>
  20. double LambertW(const double x);
  21. inline
  22. double
  23. LambertW(const int branch, const double x)
  24. {
  25. switch (branch) {
  26. case -1: return LambertW<-1>(x);
  27. case 0: return LambertW<0>(x);
  28. default: return std::numeric_limits<double>::quiet_NaN();
  29. }
  30. }
  31. }
  32. #endif