healpy.query_strip

healpy.query_strip(nside, theta1, theta2, inclusive=False, nest=False, buff=None, return_ranges=False)

Returns pixels whose centers lie within the colatitude range defined by theta1 and theta2 (if inclusive is False), or which overlap with this region (if inclusive is True). If theta1<theta2, the region between both angles is considered, otherwise the regions 0<theta<theta2 and theta1<theta<pi.

Parameters:

nsideint

The nside of the Healpix map.

theta1float

First colatitude (radians)

theta2float

Second colatitude (radians)

inclusivebool

If False, return the exact set of pixels whose pixels centers lie within the region; if True, return all pixels that overlap with the region.

nest: bool, optional

if True, assume NESTED pixel ordering, otherwise, RING pixel ordering

buff: int array, optional

if provided, this numpy array is used to contain the return values and must be at least long enough to do so. Cannot be used with return_ranges=True.

return_ranges: bool, optional

if True, return a 2D array of pixel ranges with shape (num_ranges, 2), where each row contains [start, end) of a range. This is more memory-efficient for queries returning large numbers of pixels. Default: False

Returns:

ipixint, array

If return_ranges is False: 1D array of pixel indices. If return_ranges is True: 2D array of shape (num_ranges, 2) where each row is [start, end) representing a range of pixels.