healpy.pixelfunc.nside2npix¶
- healpy.pixelfunc.nside2npix(nside)¶
Give the number of pixel for the given nside.
Parameters: nside : int
healpix nside parameter; an exception is raised if nside is not valid (nside must be a power of 2)
Returns: npix : int
corresponding number of pixels
Notes
Raise a ValueError exception if nside is not valid.
Examples
>>> import healpy as hp >>> hp.nside2npix(8) 768
>>> np.all([hp.nside2npix(nside) == 12 * nside**2 for nside in [2**n for n in range(12)]]) True
>>> hp.nside2npix(7) Traceback (most recent call last): ... ValueError: Given number is not a valid nside parameter (must be a power of 2)