diff options
Diffstat (limited to 'src/PJ_vandg4.c')
| -rw-r--r-- | src/PJ_vandg4.c | 194 |
1 files changed, 97 insertions, 97 deletions
diff --git a/src/PJ_vandg4.c b/src/PJ_vandg4.c index 4d4032b3..ca079000 100644 --- a/src/PJ_vandg4.c +++ b/src/PJ_vandg4.c @@ -1,97 +1,97 @@ -#define PJ_LIB__
-#include <projects.h>
-
-PROJ_HEAD(vandg4, "van der Grinten IV") "\n\tMisc Sph, no inv.";
-
-#define TOL 1e-10
-
-
-static XY s_forward (LP lp, PJ *P) { /* Spheroidal, forward */
- XY xy = {0.0,0.0};
- double x1, t, bt, ct, ft, bt2, ct2, dt, dt2;
- (void) P;
-
- if (fabs(lp.phi) < TOL) {
- xy.x = lp.lam;
- xy.y = 0.;
- } else if (fabs(lp.lam) < TOL || fabs(fabs(lp.phi) - M_HALFPI) < TOL) {
- xy.x = 0.;
- xy.y = lp.phi;
- } else {
- bt = fabs(M_TWO_D_PI * lp.phi);
- bt2 = bt * bt;
- ct = 0.5 * (bt * (8. - bt * (2. + bt2)) - 5.)
- / (bt2 * (bt - 1.));
- ct2 = ct * ct;
- dt = M_TWO_D_PI * lp.lam;
- dt = dt + 1. / dt;
- dt = sqrt(dt * dt - 4.);
- if ((fabs(lp.lam) - M_HALFPI) < 0.) dt = -dt;
- dt2 = dt * dt;
- x1 = bt + ct; x1 *= x1;
- t = bt + 3.*ct;
- ft = x1 * (bt2 + ct2 * dt2 - 1.) + (1.-bt2) * (
- bt2 * (t * t + 4. * ct2) +
- ct2 * (12. * bt * ct + 4. * ct2) );
- x1 = (dt*(x1 + ct2 - 1.) + 2.*sqrt(ft)) /
- (4.* x1 + dt2);
- xy.x = M_HALFPI * x1;
- xy.y = M_HALFPI * sqrt(1. + dt * fabs(x1) - x1 * x1);
- if (lp.lam < 0.) xy.x = -xy.x;
- if (lp.phi < 0.) xy.y = -xy.y;
- }
- return xy;
-}
-
-
-static void *freeup_new (PJ *P) { /* Destructor */
- if (0==P)
- return 0;
-
- return pj_dealloc(P);
-}
-
-
-static void freeup (PJ *P) {
- freeup_new (P);
- return;
-}
-
-
-PJ *PROJECTION(vandg4) {
- P->es = 0.;
- P->fwd = s_forward;
-
- return P;
-}
-
-
-#ifdef PJ_OMIT_SELFTEST
-int pj_vandg4_selftest (void) {return 0;}
-#else
-
-int pj_vandg4_selftest (void) {
- double tolerance_lp = 1e-10;
- double tolerance_xy = 1e-7;
-
- char s_args[] = {"+proj=vandg4 +a=6400000 +lat_1=0.5 +lat_2=2"};
-
- LP fwd_in[] = {
- { 2, 1},
- { 2,-1},
- {-2, 1},
- {-2,-1}
- };
-
- XY s_fwd_expect[] = {
- { 223374.57729435508, 111701.19548415358
},
- { 223374.57729435508, -111701.19548415358
},
- {-223374.57729435508, 111701.19548415358
},
- {-223374.57729435508, -111701.19548415358
},
- };
-
- return pj_generic_selftest (0, s_args, tolerance_xy, tolerance_lp, 4, 4, fwd_in, 0, s_fwd_expect, 0, 0, 0);
-}
-
-
-#endif
+#define PJ_LIB__ +#include <projects.h> + +PROJ_HEAD(vandg4, "van der Grinten IV") "\n\tMisc Sph, no inv."; + +#define TOL 1e-10 + + +static XY s_forward (LP lp, PJ *P) { /* Spheroidal, forward */ + XY xy = {0.0,0.0}; + double x1, t, bt, ct, ft, bt2, ct2, dt, dt2; + (void) P; + + if (fabs(lp.phi) < TOL) { + xy.x = lp.lam; + xy.y = 0.; + } else if (fabs(lp.lam) < TOL || fabs(fabs(lp.phi) - M_HALFPI) < TOL) { + xy.x = 0.; + xy.y = lp.phi; + } else { + bt = fabs(M_TWO_D_PI * lp.phi); + bt2 = bt * bt; + ct = 0.5 * (bt * (8. - bt * (2. + bt2)) - 5.) + / (bt2 * (bt - 1.)); + ct2 = ct * ct; + dt = M_TWO_D_PI * lp.lam; + dt = dt + 1. / dt; + dt = sqrt(dt * dt - 4.); + if ((fabs(lp.lam) - M_HALFPI) < 0.) dt = -dt; + dt2 = dt * dt; + x1 = bt + ct; x1 *= x1; + t = bt + 3.*ct; + ft = x1 * (bt2 + ct2 * dt2 - 1.) + (1.-bt2) * ( + bt2 * (t * t + 4. * ct2) + + ct2 * (12. * bt * ct + 4. * ct2) ); + x1 = (dt*(x1 + ct2 - 1.) + 2.*sqrt(ft)) / + (4.* x1 + dt2); + xy.x = M_HALFPI * x1; + xy.y = M_HALFPI * sqrt(1. + dt * fabs(x1) - x1 * x1); + if (lp.lam < 0.) xy.x = -xy.x; + if (lp.phi < 0.) xy.y = -xy.y; + } + return xy; +} + + +static void *freeup_new (PJ *P) { /* Destructor */ + if (0==P) + return 0; + + return pj_dealloc(P); +} + + +static void freeup (PJ *P) { + freeup_new (P); + return; +} + + +PJ *PROJECTION(vandg4) { + P->es = 0.; + P->fwd = s_forward; + + return P; +} + + +#ifdef PJ_OMIT_SELFTEST +int pj_vandg4_selftest (void) {return 0;} +#else + +int pj_vandg4_selftest (void) { + double tolerance_lp = 1e-10; + double tolerance_xy = 1e-7; + + char s_args[] = {"+proj=vandg4 +a=6400000 +lat_1=0.5 +lat_2=2"}; + + LP fwd_in[] = { + { 2, 1}, + { 2,-1}, + {-2, 1}, + {-2,-1} + }; + + XY s_fwd_expect[] = { + { 223374.57729435508, 111701.19548415358
}, + { 223374.57729435508, -111701.19548415358
}, + {-223374.57729435508, 111701.19548415358
}, + {-223374.57729435508, -111701.19548415358
}, + }; + + return pj_generic_selftest (0, s_args, tolerance_xy, tolerance_lp, 4, 4, fwd_in, 0, s_fwd_expect, 0, 0, 0); +} + + +#endif |