healpy.pixelfunc.npix2nside¶

healpy.pixelfunc.npix2nside(npix)¶

Give the nside parameter for the given number of pixels.

Parameters:

Returns:

Notes

Raise a ValueError exception if number of pixel does not correspond to the number of pixel of a healpix map.

Examples

>>> import healpy as hp
>>> hp.npix2nside(768)
8

>>> np.all([hp.npix2nside(12 * nside**2) == nside for nside in [2**n for n in range(12)]])
True

>>> hp.npix2nside(1000)
Traceback (most recent call last):
    ...
ValueError: Wrong pixel number (it is not 12*nside**2)

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