Columns 1..L are phi_0, ..., phi_{L-1} with
phi_k(u) = sqrt(2k+1) P_k(2u - 1), orthonormal on [0, 1]. The generalized
moment integral Q(u) phi_{r-1}(u) du is the projection of the quantile
function onto phi_{r-1}; it equals Hosking's (1990) classical L-moment up to
the sqrt(2r-1) orthonormalisation factor (phi_0 = 1, so the first equals
the mean). These orthonormal moments – not Hosking's classical scaling – are
what qfmix matches and reports.