svn-gvsig-desktop / tags / v1_10_0_Build_1261 / libraries / libjni-proj4 / src / PJ_putp2.c @ 33914
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#ifndef lint
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static const char SCCSID[]="@(#)PJ_putp2.c 4.1 94/02/15 GIE REL"; |
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#endif
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#define PJ_LIB__
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#include <projects.h> |
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PROJ_HEAD(putp2, "Putnins P2") "\n\tPCyl., Sph."; |
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#define C_x 1.89490 |
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#define C_y 1.71848 |
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#define C_p 0.6141848493043784 |
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#define EPS 1e-10 |
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#define NITER 10 |
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#define PI_DIV_3 1.0471975511965977 |
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FORWARD(s_forward); /* spheroid */
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double p, c, s, V;
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int i;
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p = C_p * sin(lp.phi); |
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s = lp.phi * lp.phi; |
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lp.phi *= 0.615709 + s * ( 0.00909953 + s * 0.0046292 ); |
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for (i = NITER; i ; --i) {
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c = cos(lp.phi); |
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s = sin(lp.phi); |
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lp.phi -= V = (lp.phi + s * (c - 1.) - p) /
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(1. + c * (c - 1.) - s * s); |
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if (fabs(V) < EPS)
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break;
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} |
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if (!i)
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lp.phi = lp.phi < 0 ? - PI_DIV_3 : PI_DIV_3;
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xy.x = C_x * lp.lam * (cos(lp.phi) - 0.5); |
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xy.y = C_y * sin(lp.phi); |
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return (xy);
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} |
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INVERSE(s_inverse); /* spheroid */
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double c;
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lp.phi = aasin(xy.y / C_y); |
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lp.lam = xy.x / (C_x * ((c = cos(lp.phi)) - 0.5)); |
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lp.phi = aasin((lp.phi + sin(lp.phi) * (c - 1.)) / C_p);
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return (lp);
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} |
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FREEUP; if (P) pj_dalloc(P); }
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ENTRY0(putp2) P->es = 0.; P->inv = s_inverse; P->fwd = s_forward; ENDENTRY(P)
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