derpol_legendre

 DERPOL_LEGENDRE  recursive construction of Legendre polynomials 1st derivative
            formula (2.3.19), pag. 77, CHQZ2

   [dlnp1]=derpol_legendre(n,ln,dln,dlnm1)

 Input: n = polynomial degree
        ln = character expression of L_n(x)
        dln = character expression of (L_n)'(x)
        dlnm1 = character expression of (L_{n-1})'(x)

 Output: dlnp1 = character expression of (L_{n+1})'(x)

 Reference: CHQZ2 = C. Canuto, M.Y. Hussaini, A. Quarteroni, T.A. Zang,
                    "Spectral Methods. Fundamentals in Single Domains"
                    Springer Verlag, Berlin Heidelberg New York, 2006.

0001 function [dlnp1]=derpol_legendre(n,ln,dln,dlnm1)
0002 % DERPOL_LEGENDRE  recursive construction of Legendre polynomials 1st derivative
0003 %            formula (2.3.19), pag. 77, CHQZ2
0004 %
0005 %   [dlnp1]=derpol_legendre(n,ln,dln,dlnm1)
0006 %
0007 % Input: n = polynomial degree
0008 %        ln = character expression of L_n(x)
0009 %        dln = character expression of (L_n)'(x)
0010 %        dlnm1 = character expression of (L_{n-1})'(x)
0011 %
0012 % Output: dlnp1 = character expression of (L_{n+1})'(x)
0013 %
0014 % Reference: CHQZ2 = C. Canuto, M.Y. Hussaini, A. Quarteroni, T.A. Zang,
0015 %                    "Spectral Methods. Fundamentals in Single Domains"
0016 %                    Springer Verlag, Berlin Heidelberg New York, 2006.
0017 
0018 %   Written by Paola Gervasio
0019 %   $Date: 2007/04/01$
0020 
0021 
0022 ns=num2str(n);
0023 dlnp1=['(2*',ns,'+1)/(',ns,'+1).*(',ln,'+x.*(',dln,'))-',ns,'/(',ns,'+1).*(',dlnm1,')'];
0024 return
0025