transformcl.corrtocl

transformcl.corrtocl(corr, closed=False)

transform angular correlation function to power spectrum

Takes an angular function in \(\mathtt{n}\) points and returns the corresponding angular power spectrum from \(0\) to \(\mathtt{lmax} = \mathtt{n}-1\).

The correlation function must be given at the angles returned by transformcl.theta(). These can be distributed either over the closed interval \([0, \pi]\), in which case \(\theta_0 = 0\) and \(\theta_{n-1} = \pi\), or over the open interval \((0, \pi)\).

Parameters:

corr(n,) array_like

Angular correlation function.

closedbool

Compute correlation function over open (closed=False) or closed (closed=True) interval.

Returns:

cl(n,) array_like

Angular power spectrum from \(0\) to \(\mathtt{lmax}\).

See also

transformcl.cltocorr

the inverse operation

transformcl.theta

compute the angles at which the correlation function is evaluated

Notes

The computation uses the discrete Legendre transform flt.dlt().