healpy.query_polygon

healpy.query_polygon()

Returns the pixels whose centers lie within the convex polygon defined by the vertices array (if inclusive is False), or which overlap with this polygon (if inclusive is True).

Parameters

nsideint

The nside of the Healpix map.

verticesfloat, array-like

Vertex array containing the vertices of the polygon, shape (N, 3).

inclusivebool, optional

If False, return the exact set of pixels whose pixel centers lie within the polygon; if True, return all pixels that overlap with the polygon, and maybe a few more. Default: False.

factint, optional

Only used when inclusive=True. The overlapping test will be done at the resolution fact*nside. For NESTED ordering, fact must be a power of 2, less than 2**30, else it can be any positive integer. Default: 4.

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

Returns

ipixint, array

The pixels which lie within the given polygon.