Re: normalized ALF (Assotiated Legendre Function)

[Marco Caliari]

Hi.

The normalized Lagrange functions should (almost) never give NaNs of Infs. 
The enclosed script fixes a problem in the previous:

octave:1> legendreold(151,-0.9,"norm")(end-1:end)
ans =

  -3.3248e-53
          Inf
octave:2> legendre(151,-0.9,"norm")(end-1:end)
ans =

  -3.3248e-53
   9.2660e-55

Marco

> "The following functions compute the associated Legendre Polynomials 
> P_l^m(x). Note that this function grows combinatorially with l and can 
> overflow for l larger than about 150. There is no trouble for small m, but 
> overflow occurs when m and l are both large. Rather than allow overflows, 
> these functions refuse to calculate P_l^m(x) and return GSL_EOVRFLW when they 
> can sense that l and m are too big."

legendre.m
Description: Text document