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.

func : callable

The transformation function. Should have a call signature func(formcoord, toframe). Note that, unlike CoordinateTransform.__call__, toframe is assumed to be of type tosys for this function.

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 or None

A graph to register this transformation with on creation, or None to leave it unregistered.


If func is not callable.


If func cannot accept two arguments.

Methods Summary

__call__(fromcoord, toframe)

Methods Documentation

__call__(fromcoord, toframe)[source]