| 1 | #include "slalib.h" | 
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| 2 | #include "slamac.h" | 
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| 3 | void slaEcleq ( double dl, double db, double date, | 
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| 4 | double *dr, double *dd) | 
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| 5 | /* | 
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| 6 | **  - - - - - - - - - | 
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| 7 | **   s l a E c l e q | 
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| 8 | **  - - - - - - - - - | 
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| 9 | ** | 
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| 10 | **  Transformation from ecliptic coordinates to J2000.0 | 
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| 11 | **  equatorial coordinates. | 
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| 12 | ** | 
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| 13 | **  (double precision) | 
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| 14 | ** | 
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| 15 | **  Given: | 
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| 16 | **     dl,db       double      ecliptic longitude and latitude | 
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| 17 | **                             (mean of date, IAU 1980 theory, radians) | 
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| 18 | **     date        double      TDB (loosely ET) as Modified Julian Date | 
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| 19 | **                                              (JD-2400000.5) | 
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| 20 | **  Returned: | 
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| 21 | **     *dr,*dd     double      J2000.0 mean RA,Dec (radians) | 
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| 22 | ** | 
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| 23 | **  Called: | 
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| 24 | **     slaDcs2c, slaEcmat, slaDimxv, slaPrec, slaEpj, slaDcc2s, | 
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| 25 | **     slaDranrm, slaDrange | 
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| 26 | ** | 
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| 27 | **  Last revision:   31 October 1993 | 
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| 28 | ** | 
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| 29 | **  Copyright P.T.Wallace.  All rights reserved. | 
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| 30 | */ | 
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| 31 | { | 
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| 32 | double rmat[3][3], v1[3], v2[3]; | 
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| 33 |  | 
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| 34 | /* Spherical to Cartesian */ | 
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| 35 | slaDcs2c ( dl, db, v1 ); | 
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| 36 |  | 
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| 37 | /* Ecliptic to equatorial */ | 
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| 38 | slaEcmat ( date, rmat ); | 
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| 39 | slaDimxv ( rmat, v1, v2 ); | 
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| 40 |  | 
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| 41 | /* Mean of date to J2000 */ | 
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| 42 | slaPrec ( 2000.0, slaEpj ( date ), rmat ); | 
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| 43 | slaDimxv ( rmat, v2, v1 ); | 
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| 44 |  | 
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| 45 | /* Cartesian to spherical */ | 
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| 46 | slaDcc2s ( v1, dr, dd ); | 
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| 47 |  | 
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| 48 | /* Express in conventional ranges */ | 
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| 49 | *dr = slaDranrm ( *dr ); | 
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| 50 | *dd = slaDrange ( *dd ); | 
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| 51 | } | 
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