Bases: object
Abstract superclass for all coordinate classes representing points in three dimensions.
Notes
Subclasses must implement __init__, and define the latangle and lonangle properties. They may also override the equinox property, or leave it unaltered to indicate the coordinates are equinoxless.
_initialize_latlon is provided to implement typical initialization features, and should be called from a subclass’ __init__. See the classes in astropy.coordinates.builtin_systems for examples of this.
Attributes Summary
cartesian | |
distance | The radial distance for this coordinate object as an Distance object. |
equinox | The equinox of this system, or None to indicate no equinox specified. |
latangle | The latitudinal/elevation angle for these coordinates as an Angle object. |
lonangle | The longitudinal/azimuthal angle for these coordinates as an Angle object. |
x | |
y | |
z |
Methods Summary
from_name(name) | Given a name, query the CDS name resolver to attempt to retrieve coordinate information for that object. |
is_transformable_to(tosys) | Determines if this coordinate can be transformed to a particular system. |
separation(other) | Computes on-sky separation between this coordinate and another. |
separation_3d(other) | Computes three dimensional separation between this coordinate and another. |
transform_to(tosys) | Transform this coordinate to a new system. |
Attributes Documentation
The radial distance for this coordinate object as an Distance object.
If set as a tuple, the tuple will be passed into the Distance constructor.
Alternatively, this may be None, indicating an unknown/not given distance. Where necessary, this object will be interpreted as angles on the unit sphere.
The latitudinal/elevation angle for these coordinates as an Angle object.
Note
This should be overridden in subclasses as a read-only property that just returns an attribute a way to abstract the exact choice of names for the coordiantes. E.g., ICRSCoordinates implements this by doing return self.ra.
The longitudinal/azimuthal angle for these coordinates as an Angle object.
Note
This should be overridden in subclasses as a read-only property that just returns an attribute a way to abstract the exact choice of names for the coordinates. E.g., ICRSCoordinates implements this by doing return self.dec.
Methods Documentation
Given a name, query the CDS name resolver to attempt to retrieve coordinate information for that object. The search database, sesame url, and query timeout can be set through configuration items in astropy.coordinates.name_resolve – see docstring for astropy.coordinates.name_resolve.get_icrs_coordinates for more information.
Parameters : | name : str
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Returns : | coord : SphericalCoordinatesBase
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Determines if this coordinate can be transformed to a particular system.
Parameters : | tosys : class
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Returns : | transformable : bool or str
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Computes on-sky separation between this coordinate and another.
See the AngularSeparation docstring for further details on the actual calculation.
Parameters : | other : SphericalCoordinatesBase
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Returns : | sep : AngularSeparation
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Computes three dimensional separation between this coordinate and another.
Parameters : | other : SphericalCoordinatesBase
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Returns : | sep : Distance
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Raises : | ValueError :
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Transform this coordinate to a new system.
Parameters : | tosys : class
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Returns : | transcoord :
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Raises : | ValueError :
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