healpy.pixelfunc.get_map_size

healpy.pixelfunc.get_map_size(m)

Returns the npix of a given map (implicit or explicit pixelization).

If map is a dict type, assumes explicit pixelization: use nside key if present, or use nside attribute if present, otherwise use the smallest valid npix given the maximum key value. otherwise assumes implicit pixelization and returns len(m).

Parameters

marray-like or dict-like

a map with implicit (array-like) or explicit (dict-like) pixellization

Returns

npixint

a valid number of pixel

Notes

In implicit pixellization, raise a ValueError exception if the size of the input is not a valid pixel number.

Examples

>>> import healpy as hp
 >>> m = {0: 1, 1: 1, 2: 1, 'nside': 1}
 >>> print(hp.get_map_size(m))
 12

>>> m = {0: 1, 767: 1}
>>> print(hp.get_map_size(m))
768

>>> print(hp.get_map_size(np.zeros(12 * 8 ** 2)))
768