healpy.sphtfunc.synalm

healpy.sphtfunc.synalm(cls, lmax=None, mmax=None, new=False, verbose=True)

Generate a set of alm given cl. The cl are given as a float array. Corresponding alm are generated. If lmax is None, it is assumed lmax=cl.size-1 If mmax is None, it is assumed mmax=lmax.

Parameters:

clsfloat, array or tuple of arrays

Either one cl (1D array) or a tuple of either 4 cl or of n*(n+1)/2 cl. Some of the cl may be None, implying no cross-correlation. See new parameter.

lmaxint, scalar, optional

The lmax (if None or <0, the largest size-1 of cls)

mmaxint, scalar, optional

The mmax (if None or <0, =lmax)

newbool, optional

If True, use the new ordering of cl’s, ie by diagonal (e.g. TT, EE, BB, TE, EB, TB or TT, EE, BB, TE if 4 cl as input). If False, use the old ordering, ie by row (e.g. TT, TE, TB, EE, EB, BB or TT, TE, EE, BB if 4 cl as input).

Returns:

almsarray or list of arrays

the generated alm if one spectrum is given, or a list of n alms (with n(n+1)/2 the number of input cl, or n=3 if there are 4 input cl).

Notes

We don’t plan to change the default order anymore, that would break old code in a way difficult to debug.