add a link to LAPACK forums

diff --git a/source/lac/lapack_full_matrix.cc b/source/lac/lapack_full_matrix.cc
index db569d11a6e978cdf424e4efd9a35b548c881122..5645f64f4e9717c49f18eea05f97feb041c68742 100644 (file)
--- a/source/lac/lapack_full_matrix.cc
+++ b/source/lac/lapack_full_matrix.cc
@@ -226,6 +226,7 @@ namespace
     // 6.5.4 Cholesky Updating and Downdating, Golub 2013 Matrix computations
     // Note that potrf() is called with LAPACKSupport::L , so the
     // factorization is stored in lower triangular part.
+    // Also see discussion here http://icl.cs.utk.edu/lapack-forum/viewtopic.php?f=2&t=2646
     if (a > 0.)
       {
         // simple update via a sequence of Givens rotations.