svn-gvsig-desktop / tags / v1_9_Build_1242 / libraries / libjni-proj4 / src / pj_tsfn.c @ 44345
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/* determine small t */
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#ifndef lint
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static const char SCCSID[]="@(#)pj_tsfn.c 4.3 93/06/12 GIE REL"; |
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#endif
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#include <math.h> |
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#include <projects.h> |
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#define HALFPI 1.5707963267948966 |
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double
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pj_tsfn(double phi, double sinphi, double e) { |
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sinphi *= e; |
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return (tan (.5 * (HALFPI - phi)) / |
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pow((1. - sinphi) / (1. + sinphi), .5 * e)); |
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} |