CoordinateTransform¶
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class
astropy.coordinates.
CoordinateTransform
(fromsys, tosys, priority=1, register_graph=None)[source] [edit on github]¶ Bases:
object
An object that transforms a coordinate from one system to another. Subclasses must implement
__call__
with the provided signature. They should also call this superclass’s__init__
in their__init__
.Parameters: fromsys : class
The coordinate frame class to start from.
tosys : class
The coordinate frame class to transform into.
priority : number
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.Methods Summary
Methods Documentation
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__call__
(fromcoord, toframe)[source] [edit on github]¶ Does the actual coordinate transformation from the
fromsys
class to thetosys
class.Parameters: fromcoord : fromsys object
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.Returns: tocoord : tosys object
The new coordinate after the transform has been applied.
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register
(graph)[source] [edit on github]¶ Add this transformation to the requested Transformation graph, replacing anything already connecting these two coordinates.
Parameters: graph : a TransformGraph object
The graph to register this transformation with.
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unregister
(graph)[source] [edit on github]¶ Remove this transformation from the requested transformation graph.
Parameters: graph : a TransformGraph object
The graph to unregister this transformation from.
Raises: ValueError
If this is not currently in the transform graph.
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