/Proj4/PJ_loxim.c

http://github.com/route-me/route-me · C · 44 lines · 44 code · 0 blank · 0 comment · 8 complexity · 8ad24112c66d8685ca14a3a171c8515a MD5 · raw file 

    

  1. #ifndef lint
    2. 

  2. static const char SCCSID[]="@(#)PJ_loxim.c	4.1 94/02/15     GIE     REL";
    3. 

  3. #endif
    4. 

  4. #define PROJ_PARMS__ \
    5. 

  5. 	double phi1; \
    6. 

  6. 	double cosphi1; \
    7. 

  7. 	double tanphi1;
    8. 

  8. #define PJ_LIB__
    9. 

  9. #include	"projects.h"
    10. 

  10. PROJ_HEAD(loxim, "Loximuthal") "\n\tPCyl Sph";
    11. 

  11. #define EPS	1e-8
    12. 

  12. FORWARD(s_forward); /* spheroid */
    13. 

  13. 	xy.y = lp.phi - P->phi1;
    14. 

  14. 	if (fabs(xy.y) < EPS)
    15. 

  15. 		xy.x = lp.lam * P->cosphi1;
    16. 

  16. 	else {
    17. 

  17. 		xy.x = FORTPI + 0.5 * lp.phi;
    18. 

  18. 		if (fabs(xy.x) < EPS || fabs(fabs(xy.x) - HALFPI) < EPS)
    19. 

  19. 			xy.x = 0.;
    20. 

  20. 		else
    21. 

  21. 			xy.x = lp.lam * xy.y / log( tan(xy.x) / P->tanphi1 );
    22. 

  22. 	}
    23. 

  23. 	return (xy);
    24. 

  24. }
    25. 

  25. INVERSE(s_inverse); /* spheroid */
    26. 

  26. 	lp.phi = xy.y + P->phi1;
    27. 

  27. 	if (fabs(xy.y) < EPS)
    28. 

  28. 		lp.lam = xy.x / P->cosphi1;
    29. 

  29. 	else
    30. 

  30. 		if (fabs( lp.lam = FORTPI + 0.5 * lp.phi ) < EPS ||
    31. 

  31. 			fabs(fabs(lp.lam) - HALFPI) < EPS)
    32. 

  32. 			lp.lam = 0.;
    33. 

  33. 		else
    34. 

  34. 			lp.lam = xy.x * log( tan(lp.lam) / P->tanphi1 ) / xy.y ;
    35. 

  35. 	return (lp);
    36. 

  36. }
    37. 

  37. FREEUP; if (P) pj_dalloc(P); }
    38. 

  38. ENTRY0(loxim);
    39. 

  39. 	P->phi1 = pj_param(P->params, "rlat_1").f;
    40. 

  40. 	if ((P->cosphi1 = cos(P->phi1)) < EPS) E_ERROR(-22);
    41. 

  41. 	P->tanphi1 = tan(FORTPI + 0.5 * P->phi1);
    42. 

  42. 	P->inv = s_inverse; P->fwd = s_forward;
    43. 

  43. 	P->es = 0.;
    44. 

  44. ENDENTRY(P)
    45.