EVOLUTION-MANAGER

Edit File: PJ_fahey.c

#define PJ_LIB__ #include <math.h> #include "projects.h" PROJ_HEAD(fahey, "Fahey") "\n\tPcyl, Sph."; #define TOL 1e-6 static XY s_forward (LP lp, PJ *P) { /* Spheroidal, forward */ XY xy = {0.0,0.0}; (void) P; xy.x = tan(0.5 * lp.phi); xy.y = 1.819152 * xy.x; xy.x = 0.819152 * lp.lam * asqrt(1 - xy.x * xy.x); return xy; } static LP s_inverse (XY xy, PJ *P) { /* Spheroidal, inverse */ LP lp = {0.0,0.0}; (void) P; xy.y /= 1.819152; lp.phi = 2. * atan(xy.y); xy.y = 1. - xy.y * xy.y; lp.lam = fabs(xy.y) < TOL ? 0. : xy.x / (0.819152 * sqrt(xy.y)); return lp; } PJ *PROJECTION(fahey) { P->es = 0.; P->inv = s_inverse; P->fwd = s_forward; return P; }