I found in the Healpy documentation that
healpy.anafast has a default value for lmax of 3*nside-1
Is there a reason for this standard? Is it a standard within HEALPix, a standard for CMB experiments, or may it has physical reasons?
Edited: When I run
anafast on a sky map
Nside=4, the number of Cl values I get is of length = 12. That makes me think that lmax should be
However, when using generated Cl values, the first two numbers are equal to zero: the monopole is zero, the dipole is zero.
Therefore, when I set the l values by
np.arange(len(Clvalues)), should I also remove the terms
[0,1] for the monopole and dipole?