diff options
author | Joe Hunkeler <jhunkeler@gmail.com> | 2015-08-11 16:51:37 -0400 |
---|---|---|
committer | Joe Hunkeler <jhunkeler@gmail.com> | 2015-08-11 16:51:37 -0400 |
commit | 40e5a5811c6ffce9b0974e93cdd927cbcf60c157 (patch) | |
tree | 4464880c571602d54f6ae114729bf62a89518057 /math/slalib/doc/tps2c.hlp | |
download | iraf-osx-40e5a5811c6ffce9b0974e93cdd927cbcf60c157.tar.gz |
Repatch (from linux) of OSX IRAF
Diffstat (limited to 'math/slalib/doc/tps2c.hlp')
-rw-r--r-- | math/slalib/doc/tps2c.hlp | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/math/slalib/doc/tps2c.hlp b/math/slalib/doc/tps2c.hlp new file mode 100644 index 00000000..d1914ef2 --- /dev/null +++ b/math/slalib/doc/tps2c.hlp @@ -0,0 +1,58 @@ +.help tps2c Jun99 "Slalib Package" +.nf + + SUBROUTINE slTPSC (XI, ETA, RA, DEC, RAZ1, DECZ1, + : RAZ2, DECZ2, N) + + - - - - - - + T P S C + - - - - - - + + From the tangent plane coordinates of a star of known RA,Dec, + determine the RA,Dec of the tangent point. + + (single precision) + + Given: + XI,ETA r tangent plane rectangular coordinates + RA,DEC r spherical coordinates + + Returned: + RAZ1,DECZ1 r spherical coordinates of tangent point, solution 1 + RAZ2,DECZ2 r spherical coordinates of tangent point, solution 2 + N i number of solutions: + 0 = no solutions returned (note 2) + 1 = only the first solution is useful (note 3) + 2 = both solutions are useful (note 3) + + Notes: + + 1 The RAZ1 and RAZ2 values are returned in the range 0-2pi. + + 2 Cases where there is no solution can only arise near the poles. + For example, it is clearly impossible for a star at the pole + itself to have a non-zero XI value, and hence it is + meaningless to ask where the tangent point would have to be + to bring about this combination of XI and DEC. + + 3 Also near the poles, cases can arise where there are two useful + solutions. The argument N indicates whether the second of the + two solutions returned is useful. N=1 indicates only one useful + solution, the usual case; under these circumstances, the second + solution corresponds to the "over-the-pole" case, and this is + reflected in the values of RAZ2 and DECZ2 which are returned. + + 4 The DECZ1 and DECZ2 values are returned in the range +/-pi, but + in the usual, non-pole-crossing, case, the range is +/-pi/2. + + 5 This routine is the spherical equivalent of the routine slDPVC. + + Called: slRA2P + + P.T.Wallace Starlink 5 June 1995 + + Copyright (C) 1995 Rutherford Appleton Laboratory + Copyright (C) 1995 Association of Universities for Research in Astronomy Inc. + +.fi +.endhelp |