Documentation Suggestion

[m elmer]

Howdy GSL Team!
 
First, I just wanted to thank y'all for maintaining this library. Its C 
approach makes its many functionalities incredibly convenient. I only ran into 
one small issue.
 
In the Gauss-Legendre integration 
https://www.gnu.org/software/gsl/doc/html/integration.html#gauss-legendre-integration
 section, I couldn't find any information on how the 
gsl_integration_glfixed_table stored the nodes and weights. Since it wasn't 
documented, I assumed that all n nodes and n weights were stored in the x and w 
arrays, respectively, and got some very confusing results. After printing n 
values from each of the x and w arrays, I discovered that it doesn't store the 
negative values, presumably to save memory. I realize that I should have been 
using gsl_integration_glfixed_point in the first place, but there was nothing 
that said so or warned me against directly accessing 
gsl_integration_glfixed_table.
 
So that others don't make the same mistake I did, would anyone be willing to 
add a few sentences to the description of gsl_integration_glfixed_table? My 
suggestion is as follows:
 
"To save memory, this table does not store the negative nodes or weights for 
the quadrature, since they are the same absolute value as the positive nodes 
and weights, respectively. The non-negative values stored are ordered by 
increasing value, and a desired point is easily retrieved for any integration 
interval using the function gsl_integration_glfixed_point."
 
Thank you for considering my suggestion.
 
-Matt