Gauss-Legendre quadrature.
Computes the sample points and weights for Gauss-Legendre quadrature.
These sample points and weights will correctly integrate polynomials of
degree 
 or less over the interval 
 with
the weight function 
.
| Parameters : | deg : int 
  | 
|---|---|
| Returns : | x : ndarray 
 y : ndarray 
  | 
Notes
The results have only been tested up to degree 100, higher degrees may be problematic. The weights are determined by using the fact that

where 
 is a constant independent of 
 and 
is the k’th root of 
, and then scaling the results to get
the right value when integrating 1.