cdshealpix.nested.xy_to_lonlat¶
- cdshealpix.nested.xy_to_lonlat(x, y, num_threads=0)¶
Project coordinates from the HEALPix space to the sky coordinate space.
- Parameters:
- x
numpy.ndarray Position on the X axis of the HEALPix plane, \(x \in [0, 8[\)
- y
numpy.ndarray Position on the Y axis of the HEALPix plane, \(y \in [-2, 2]\)
- num_threadsint, optional
Specifies the number of threads to use for the computation. Default to 0 means it will choose the number of threads based on the RAYON_NUM_THREADS environment variable (if set), or the number of logical CPUs (otherwise)
- x
- Returns:
- (lon, lat)(
astropy.coordinates.Longitude,astropy.coordinates.Latitude) The coordinates on the sky
- (lon, lat)(
Examples
>>> from cdshealpix import xy_to_lonlat >>> import astropy.units as u >>> import numpy as np >>> x = np.array([0.5, 1.5]) >>> y = np.array([0.5, 0.5]) >>> lon, lat = xy_to_lonlat(x, y)