healpix_geo.zuniq.from_nested#

healpix_geo.zuniq.from_nested(ipix, depth, num_threads=0)#

Convert from nested to zuniq

Parameters:

  • ipix (numpy.ndarray) – The HEALPix cell indexes in the nested scheme given as a np.uint64 numpy array.

  • depth (int or numpy.ndarray of int) – The HEALPix cell depth given as scalar or a np.uint8 numpy array.

  • num_threads (int, 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)

Returns:

zuniq (numpy.ndarray of int) – The cell ids in the zuniq scheme.

Examples

>>> import healpix_geo.zuniq
>>> import numpy as np
>>> ipix_nested = np.array([32, 125, 45, 91], dtype="uint64")
>>> depth = np.array([1, 3, 2, 4], dtype="uint8")
>>> ipix_zuniq = healpix_geo.zuniq.from_nested(ipix_nested, depth)
>>> ipix_zuniq
array([4683743612465315840, 1130403506469994496, 1639310264362860544,
        206039682952200192], dtype=uint64)