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Note

This is an old version of the documentation. See http://docs.astropy.org/en/stable for the latest version.

Longitude

class astropy.coordinates.Longitude[source] [edit on github]

Bases: astropy.coordinates.Angle

Longitude-like angle(s) which are wrapped within a contiguous 360 degree range.

A Longitude object is distinguished from a pure Angle by virtue of a wrap_angle property. The wrap_angle specifies that all angle values represented by the object will be in the range:

wrap_angle - 360 * u.deg <= angle(s) < wrap_angle

The default wrap_angle is 360 deg. Setting wrap_angle=180 * u.deg would instead result in values between -180 and +180 deg. Setting the wrap_angle attribute of an existing Longitude object will result in re-wrapping the angle values in-place.

The input angle(s) can be specified either as an array, list, scalar, tuple, string, Quantity or another Angle.

The input parser is flexible and supports all of the input formats supported by Angle.

Parameters:

angle : array, list, scalar, Quantity,

Angle The angle value(s). If a tuple, will be interpreted as (h, m s) or (d, m, s) depending on unit. If a string, it will be interpreted following the rules described for Angle.

If angle is a sequence or array of strings, the resulting values will be in the given unit, or if None is provided, the unit will be taken from the first given value.

unit : UnitBase, str, optional

The unit of the value specified for the angle. This may be any string that Unit understands, but it is better to give an actual unit object. Must be an angular unit.

wrap_angle : Angle or equivalent, or None

Angle at which to wrap back to wrap_angle - 360 deg. If None (default), it will be taken to be 360 deg unless angle has a wrap_angle attribute already (i.e., is a Longitude), in which case it will be taken from there.

Raises:

`~astropy.units.UnitsError`

If a unit is not provided or it is not an angular unit.

`TypeError`

If the angle parameter is an instance of Latitude.

Attributes Summary

wrap_angle

Attributes Documentation

wrap_angle

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