FunctionTransform¶

class
astropy.coordinates.
FunctionTransform
(func, fromsys, tosys, priority=1, register_graph=None)[source]¶ Bases:
astropy.coordinates.CoordinateTransform
A coordinate transformation defined by a function that accepts a coordinate object and returns the transformed coordinate object.
 Parameters
 funccallable
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.
 prioritynumber
The priority if this transform when finding the shortest coordinate transform path  large numbers are lower priorities.
 register_graph
TransformGraph
orNone
A graph to register this transformation with on creation, or
None
to leave it unregistered.
 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
 fromcoordfromsys object
An object of class matching
fromsys
that is to be transformed. toframeobject
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.
 Returns
 tocoordtosys object
The new coordinate after the transform has been applied.