FunctionTransform¶
- class astropy.coordinates.FunctionTransform(func, fromsys, tosys, priority=1, register_graph=None)[source]¶
Bases:
CoordinateTransform
A coordinate transformation defined by a function that accepts a coordinate object and returns the transformed coordinate object.
- Parameters:
- func
python:callable()
The transformation function. Should have a call signature
func(formcoord, toframe)
. Note that, unlikeCoordinateTransform.__call__
,toframe
is assumed to be of typetosys
for this function.- 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.
- func
- Raises:
TypeError
If
func
is not callable.ValueError
If
func
cannot accept two arguments.
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
tosys.frame_attributes
. 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