How Do HEALPix FITS Files Of CMB Maps Translate Into Ndarrays? What Are The Coordinates?

I'm using Healpy (the HEALPix tools developed in Python) to read and write full-sky CMB maps. I am confused as to how the coordinates of pixels on a sky map translates into entrie

Solution 1:

the best source of information about the HEALPIX pixelization is the Healpix primer:

http://healpix.jpl.nasa.gov/html/intro.htm

A map is a 1-dimensional vector, each index is a pixel in the sky. you can turn pixel number into coordinates in the sky using hp.pix2ang.

Shaping it in rows of 1024 is just a trick to make read/write to disk faster.