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JEphem Ephemeris trail Handling frames 

Handling frames 
Here, we see the classes used to represent frames and deal with coordinate transformations.

jephem.astro.spacetime.SpaceConstants
are used.
jephem.astro.spacetime.SpaceConstants
; these names are use throughout the program to designate the different frames.
API name  Description  Names of the spherical coordinates (order : r, q, j) 

FRAME_THEORY 
The coordinates are expressed as given by the theory used to compute them, without any transformation.
Center : depends on the theory Ref. plane : depends on the theory Ref. axis : depends on the theory Reference system : depends on the theory Geometric coordinates 
Depends on the theory 
FRAME_EC_HELIO_GEOMETRIC 
Center : Sun
Ref. plane : Mean ecliptic J2000 Ref. axis : Mean equinox J2000 Reference system : FK5 Geometric coordinates 
(D, b, l) 
FRAME_ECLIPTIC 
Center : Earth
Ref. plane : Mean ecliptic of date Ref. axis : True equinox J2000 Reference system : FK5 Apparent coordinates 
(r, l, b) 
FRAME_EQUATORIAL 
Center : Earth
Ref. plane : True Equator of date Ref. axis : True equinox J2000 Reference system : FK5 Apparent coordinates 
(r, a, d) 
jephem.astro.spacetime.Space.getFrameLabel(int whichFrame)
permits to get the English name of a given frame.
jephem.astro.spacetime.Space
and jephem.astro.spacetime.SpaceConstants
.
SpaceConstants.COORD_xx
) permit to identyify a coordinate.SpaceConstants.COORDGROUP_XXX
). Groups are accessed with Space.getCoordGroup(int frame, int sphereCart)
This is useful to get the labels.