functions in legndr.i - l

             legndr(l,m, x)  
 
     return the associated Legendre function Plm(x).  The X may  
     be an array (-1<=x<=1), but L and M (0<=M<=L) must be scalar  
     values.  For m=0, these are the Legendre polynomials Pl(x).  
     Relation of Plm(x) to Pl(x):  
       Plm(x) = (-1)^m (1-x^2)^(m/2) d^m/dx^m(Pl(x))  
     Relation of Plm(x) to spherical harmonics Ylm:  
       Ylm(theta,phi)= sqrt((2*l+1)(l-m)!/(4*pi*(l+m)!)) *  
                           Plm(cos(theta)) * exp(1i*m*phi)  
interpreted function, defined at i/legndr.i   line 12