healpy.pixelfunc.nside2resol

healpy.pixelfunc.nside2resol(nside, arcmin=False)

Give approximate resolution for nside.

Resolution is just the square root of the pixel area, which is a gross approximation given the different pixel shapes

Parameters :

nside : int

healpix nside parameter, must be a power of 2

arcmin : bool

if True, return resolution in arcmin, otherwise in radian

Returns :

resol : float

approximate pixel size in radians or arcmin

Notes

Raise a ValueError exception if nside is not valid.

Examples

>>> import healpy as hp
>>> hp.nside2resol(128, arcmin = True)
27.483891294539248

>>> hp.nside2resol(256)
0.0039973699529159707

>>> hp.nside2resol(7)
Traceback (most recent call last):
   ...
ValueError: Given number is not a valid nside parameter (must be a power of 2)