MapCoord#

class gammapy.maps.MapCoord(data, frame=None, match_by_name=True)[source]#

Bases: object

Represents a sequence of n-dimensional map coordinates.

Contains coordinates for 2 spatial dimensions and an arbitrary number of additional non-spatial dimensions. Ensure correct broadcasting of the array to allow for this.

For further information and examples see MapCoord.

Parameters:

datadict of ndarray: Dictionary of coordinate arrays.
frame{None, “icrs”, “galactic”}: Spatial coordinate system. If None then the coordinate system will be set to the native coordinate system of the geometry. Default is None.
match_by_namebool, optional: Match coordinates to axes by name. If False, coordinates will be matched by index. Default is True.

Attributes Summary

`axis_names`	Names of axes.
`broadcasted`	Return broadcasted coordinates.
`flat`	Return flattened, valid coordinates.
`frame`	Coordinate system as a string.
`lat`	Latitude coordinate in degrees.
`lon`	Longitude coordinate in degrees.
`match_by_name`	Boolean flag: axis lookup by name return True or by index return False.
`ndim`	Number of dimensions.
`phi`	Phi longitude angle in radians.
`shape`	Coordinate array shape.
`size`	Product of all shape elements.
`skycoord`	Coordinate object as a `SkyCoord`.
`theta`	Theta co-latitude angle in radians.

Methods Summary

`apply_mask`(mask)	Return a masked copy of this coordinate object.
`copy`()	Copy `MapCoord` object.
`create`(data[, frame, axis_names])	Create a new `MapCoord` object.
`to_frame`(frame)	Convert to a different coordinate frame.

Attributes Documentation

axis_names#: Names of axes.

broadcasted#: Return broadcasted coordinates.

flat#: Return flattened, valid coordinates.

frame#: Coordinate system as a string.

lat#: Latitude coordinate in degrees.

lon#: Longitude coordinate in degrees.

match_by_name#: Boolean flag: axis lookup by name return True or by index return False.

ndim#: Number of dimensions.

phi#: Phi longitude angle in radians.

shape#: Coordinate array shape.

size#: Product of all shape elements.

skycoord#: Coordinate object as a SkyCoord.

theta#: Theta co-latitude angle in radians.

Methods Documentation

apply_mask(mask)[source]#

Return a masked copy of this coordinate object.

Parameters:

maskndarray: Boolean mask.

Returns:

coordsMapCoord: A coordinates object.

copy()[source]#: Copy MapCoord object.

classmethod create(data, frame=None, axis_names=None)[source]#

Create a new MapCoord object.

This method can be used to create either unnamed (with tuple input) or named (via dict input) axes.

Parameters:

datatuple, dict, MapCoord or SkyCoord: Object containing coordinate arrays.
frame{“icrs”, “galactic”, None}: Set the coordinate system for longitude and latitude. If None longitude and latitude will be assumed to be in the coordinate system native to a given map geometry. Default is None.
axis_nameslist of str, optional: Axis names uses if a tuple is provided. Default is None.

Examples

>>> from astropy.coordinates import SkyCoord
>>> from gammapy.maps import MapCoord

>>> lon, lat = [1, 2], [2, 3]
>>> skycoord = SkyCoord(lon, lat, unit='deg')
>>> energy = [1000]
>>> c = MapCoord.create((lon,lat))
>>> c = MapCoord.create((skycoord,))
>>> c = MapCoord.create((lon,lat,energy))
>>> c = MapCoord.create(dict(lon=lon,lat=lat))
>>> c = MapCoord.create(dict(lon=lon,lat=lat,energy=energy))
>>> c = MapCoord.create(dict(skycoord=skycoord,energy=energy))

to_frame(frame)[source]#

Convert to a different coordinate frame.

Parameters:

frame{“icrs”, “galactic”}: Coordinate system, either Galactic (“galactic”) or Equatorial (“icrs”).

Returns:

coordsMapCoord: A coordinates object.