Legendre polynomials

Returns the Legendre polynomials up to specified order, orthogonal on specified interval

Instead of returning the value of a Legendre polynomial for specified values of x, this function returns the polynomial coefficients. By default they will be orthogonal on (-1,1) but by adding xmin and xmax in the call the polynomials will be orthogonal on (xmin, xmax). Having the polynomials will speed up calculations in many applications such as in solving PDE problems with MWR-methods.