healpy.hotspots

healpy.hotspots(m)

Find extrema in the 2-D field on the sphere.

This routine finds the local extrema by comparing each pixel to its 8 (or 7) immediate neighbours. This can be used (for example) to compute a projection of the angular correlation function of the CMB. Applications of this function can be found in WMAP paper (https://arxiv.org/pdf/1001.4538.pdf) as well as recent work done by Planck (https://arxiv.org/pdf/1303.5062.pdf, https://arxiv.org/abs/1506.07135).

Parameters:

marray-like, shape (Npix,)

The input map.

Returns:

outmaparray-like, shape (Npix,)

Out map of extrema (other pixels are set to UNSEEN)

min_pixelsarray_like

Pixel number for minima

max_pixelsarray_like

Pixel number for maxima