healpy.pixelfunc.ud_grade¶
-
healpy.pixelfunc.
ud_grade
(map_in, *args, **kwds)¶ Upgrade or degrade resolution of a map (or list of maps).
in degrading the resolution, ud_grade sets the value of the superpixel as the mean of the children pixels.
Parameters: map_in : array-like or sequence of array-like
the input map(s) (if a sequence of maps, all must have same size)
nside_out : int
the desired nside of the output map(s)
pess : bool
if
True
, in degrading, reject pixels which contains a bad sub_pixel. Otherwise, estimate average with good pixelsorder_in, order_out : str
pixel ordering of input and output (‘RING’ or ‘NESTED’)
power : float
if non-zero, divide the result by (nside_in/nside_out)**power Examples: power=-2 keeps the sum of the map invariant (useful for hitmaps), power=2 divides the mean by another factor of (nside_in/nside_out)**2 (useful for variance maps)
dtype : type
the type of the output map
Returns: map_out : array-like or sequence of array-like
the upgraded or degraded map(s)
Examples
>>> import healpy as hp >>> hp.ud_grade(np.arange(48.), 1) array([ 5.5 , 7.25, 9. , 10.75, 21.75, 21.75, 23.75, 25.75, 36.5 , 38.25, 40. , 41.75])