EVOLUTION-MANAGER

Edit File: PJ_eck2.c

#define PJ_LIB__ # include <projects.h> PROJ_HEAD(eck2, "Eckert II") "\n\tPCyl. Sph."; #define FXC 0.46065886596178063902 #define FYC 1.44720250911653531871 #define C13 0.33333333333333333333 #define ONEEPS 1.0000001 FORWARD(s_forward); /* spheroid */ xy.x = FXC * lp.lam * (xy.y = sqrt(4. - 3. * sin(fabs(lp.phi)))); xy.y = FYC * (2. - xy.y); if ( lp.phi < 0.) xy.y = -xy.y; return (xy); } INVERSE(s_inverse); /* spheroid */ lp.lam = xy.x / (FXC * ( lp.phi = 2. - fabs(xy.y) / FYC) ); lp.phi = (4. - lp.phi * lp.phi) * C13; if (fabs(lp.phi) >= 1.) { if (fabs(lp.phi) > ONEEPS) I_ERROR else lp.phi = lp.phi < 0. ? -HALFPI : HALFPI; } else lp.phi = asin(lp.phi); if (xy.y < 0) lp.phi = -lp.phi; return (lp); } FREEUP; if (P) pj_dalloc(P); } ENTRY0(eck2); P->es = 0.; P->inv = s_inverse; P->fwd = s_forward; ENDENTRY(P)