CoordinateAttribute

class astropy.coordinates.CoordinateAttribute(frame, default=None, secondary_attribute='')

Bases: astropy.coordinates.Attribute

A frame attribute which is a coordinate object. It can be given as a SkyCoord or a low-level frame instance. If a low-level frame instance is provided, it will always be upgraded to be a SkyCoord to ensure consistent transformation behavior. The coordinate object will always be returned as a low-level frame instance when accessed.

Parameters

framea coordinate frame class

The type of frame this attribute can be

defaultobject

Default value for the attribute if not provided

secondary_attributestr

Name of a secondary instance attribute which supplies the value if default is None and no value was supplied during initialization.

Methods Summary

convert_input(value)

Checks that the input is a SkyCoord with the necessary units (or the special value None).

Methods Documentation

convert_input(value)

Checks that the input is a SkyCoord with the necessary units (or the special value None).

Parameters

valueobject

Input value to be converted.

Returns

out, convertedcorrectly-typed object, boolean

Tuple consisting of the correctly-typed object and a boolean which indicates if conversion was actually performed.

Raises

ValueError

If the input is not valid for this attribute.