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| author | Frank Warmerdam <warmerdam@pobox.com> | 1999-03-18 16:34:52 +0000 |
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| committer | Frank Warmerdam <warmerdam@pobox.com> | 1999-03-18 16:34:52 +0000 |
| commit | 565a4bd035b9d4a83955808efef20f1d8dfa24cf (patch) | |
| tree | 75785fc897708023f1ccdaf40079afcbaaf0fd3a /src/PJ_hatano.c | |
| download | PROJ-565a4bd035b9d4a83955808efef20f1d8dfa24cf.tar.gz PROJ-565a4bd035b9d4a83955808efef20f1d8dfa24cf.zip | |
New
git-svn-id: http://svn.osgeo.org/metacrs/proj/trunk@776 4e78687f-474d-0410-85f9-8d5e500ac6b2
Diffstat (limited to 'src/PJ_hatano.c')
| -rw-r--r-- | src/PJ_hatano.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/src/PJ_hatano.c b/src/PJ_hatano.c new file mode 100644 index 00000000..8b661b3c --- /dev/null +++ b/src/PJ_hatano.c @@ -0,0 +1,53 @@ +#ifndef lint +static const char SCCSID[]="@(#)PJ_hatano.c 4.1 94/02/15 GIE REL"; +#endif +#define PJ_LIB__ +#include <projects.h> +PROJ_HEAD(hatano, "Hatano Asymmetrical Equal Area") "\n\tPCyl, Sph."; +#define NITER 20 +#define EPS 1e-7 +#define ONETOL 1.000001 +#define CN 2.67595 +#define CS 2.43763 +#define RCN 0.37369906014686373063 +#define RCS 0.41023453108141924738 +#define FYCN 1.75859 +#define FYCS 1.93052 +#define RYCN 0.56863737426006061674 +#define RYCS 0.51799515156538134803 +#define FXC 0.85 +#define RXC 1.17647058823529411764 +FORWARD(s_forward); /* spheroid */ + double th1, c; + int i; + + c = sin(lp.phi) * (lp.phi < 0. ? CS : CN); + for (i = NITER; i; --i) { + lp.phi -= th1 = (lp.phi + sin(lp.phi) - c) / (1. + cos(lp.phi)); + if (fabs(th1) < EPS) break; + } + xy.x = FXC * lp.lam * cos(lp.phi *= .5); + xy.y = sin(lp.phi) * (lp.phi < 0. ? FYCS : FYCN); + return (xy); +} +INVERSE(s_inverse); /* spheroid */ + double th; + + th = xy.y * ( xy.y < 0. ? RYCS : RYCN); + if (fabs(th) > 1.) + if (fabs(th) > ONETOL) I_ERROR + else th = th > 0. ? HALFPI : - HALFPI; + else + th = asin(th); + lp.lam = RXC * xy.x / cos(th); + th += th; + lp.phi = (th + sin(th)) * (xy.y < 0. ? RCS : RCN); + if (fabs(lp.phi) > 1.) + if (fabs(lp.phi) > ONETOL) I_ERROR + else lp.phi = lp.phi > 0. ? HALFPI : - HALFPI; + else + lp.phi = asin(lp.phi); + return (lp); +} +FREEUP; if (P) pj_dalloc(P); } +ENTRY0(hatano) P->es = 0.; P->inv = s_inverse; P->fwd = s_forward; ENDENTRY(P) |