# healpy.boundaries¶

healpy.boundaries()

Returns an array containing vectors to the boundary of the nominated pixel.

The returned array has shape (3, 4*step), the elements of which are the x,y,z positions on the unit sphere of the pixel boundary. In order to get vector positions for just the corners, specify step=1.

Parameters
nsideint

The nside of the Healpix map.

pixint

Pixel identifier

stepint, optional

Number of elements for each side of the pixel.

nestbool, optional

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

Returns
boundaryfloat, array

x,y,z for positions on the boundary of the pixel