title: UMFPACK and BOOST's uBLAS Sparse Matrix
body: <p>I am using Boost's uBLAS in a numerical code and have a 'heavy' solver in place:</p>
  
  <p><a href="http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl?LU_Matrix_Inversion" rel="nofollow">http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl?LU_Matrix_Inversion</a></p>
  
  <p>The code works excellently, however, it is painfully slow.  After some research, I found <a href="http://www.cise.ufl.edu/research/sparse/umfpack/" rel="nofollow">UMFPACK</a>, which is a sparse matrix solver (among other things).  My code generates large sparse matrices which I need to invert very frequently (more correctly solve, the value of the inverse matrix is irrelevant), so UMFPACk and BOOST's Sparse_Matrix class seems to be a happy marriage.  </p>
  
  <p>UMFPACK asks for the sparse matrix specified by three vectors: an entry count, row indexes, and the entries. (<a href="http://www.math.umbc.edu/~rouben/2003-09-math625/umfpack-ex1.c" rel="nofollow">See example</a>).</p>
  
  <p>My question boils down to, can I get these three vectors efficiently from BOOST's Sparse Matrix class?</p>