AffineTransform¶
-
class
astropy.coordinates.
AffineTransform
(transform_func, fromsys, tosys, priority=1, register_graph=None)[source]¶ Bases:
astropy.coordinates.BaseAffineTransform
A coordinate transformation specified as a function that yields a 3 x 3 cartesian transformation matrix and a tuple of displacement vectors.
See
Galactocentric
for an example.- Parameters
- transform_func
python:callable()
A callable that has the signature
transform_func(fromcoord, toframe)
and returns: a (3, 3) matrix that operates onfromcoord
in a Cartesian representation, and aCartesianRepresentation
with (optionally) an attached velocityCartesianDifferential
to represent a translation and offset in velocity to apply after the matrix operation.- fromsysclass
The coordinate frame class to start from.
- tosysclass
The coordinate frame class to transform into.
- priority
python:float
orpython:int
The priority if this transform when finding the shortest coordinate transform path - large numbers are lower priorities.
- register_graph
TransformGraph
orpython:None
A graph to register this transformation with on creation, or
None
to leave it unregistered.
- transform_func
- Raises
TypeError
If
transform_func
is not callable
Methods Summary
__call__
(fromcoord, toframe)Does the actual coordinate transformation from the
fromsys
class to thetosys
class.Methods Documentation
-
__call__
(fromcoord, toframe)[source]¶ Does the actual coordinate transformation from the
fromsys
class to thetosys
class.- Parameters
- fromcoord
BaseCoordinateFrame
subclass instance An object of class matching
fromsys
that is to be transformed.- toframe
object
An object that has the attributes necessary to fully specify the frame. That is, it must have attributes with names that match the keys of the dictionary that
tosys.get_frame_attr_names()
returns. Typically this is of classtosys
, but it might be some other class as long as it has the appropriate attributes.
- fromcoord
- Returns
- tocoord
BaseCoordinateFrame
subclass instance The new coordinate after the transform has been applied.
- tocoord