Zoltan2 Version of the Day
Zoltan2_AlgIncDegree.hpp
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00005 //   Zoltan2: A package of combinatorial algorithms for scientific computing
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00045 #ifndef _ZOLTAN2_INCDEGREE_HPP_
00046 #define _ZOLTAN2_INCDEGREE_HPP_
00047 
00048 #include <Zoltan2_GraphModel.hpp>
00049 #include <Zoltan2_OrderingSolution.hpp>
00050 #include <algorithm>
00051 
00052 
00056 
00057 // Comparison function for sort.
00058 bool comp(std::pair<lno_t,lno_t> a, std::pair<lno_t,lno_t> b)
00059 {
00060   return (a.first < b.first);
00061 }
00062 
00063 namespace Zoltan2{
00064 
00065 template <typename Adapter>
00066 int AlgIncDegree(
00067   const RCP<GraphModel<Adapter> > &model, 
00068   const RCP<OrderingSolution<typename Adapter::gid_t,
00069                              typename Adapter::lno_t> > &solution,
00070   const RCP<Teuchos::ParameterList> &pl,
00071   const RCP<Teuchos::Comm<int> > &comm
00072 ) 
00073 {
00074 #ifndef INCLUDE_ZOLTAN2_EXPERIMENTAL
00075 
00076   int ierr= 0;
00077   Z2_THROW_EXPERIMENTAL("Zoltan2 IncreasingDegree ordering is strictly "
00078                         "experimental software "
00079                         "while it is being developed and tested.")
00080   return ierr;
00081 
00082 #else //INCLUDE_ZOLTAN2_EXPERIMENTAL
00083 
00084   typedef typename Adapter::lno_t lno_t;
00085   typedef typename Adapter::gno_t gno_t;
00086   typedef typename Adapter::gid_t gid_t;
00087   typedef typename Adapter::scalar_t scalar_t;
00088 
00089   int ierr= 0;
00090 
00091   HELLO;
00092 
00093   lno_t *perm;
00094   perm = (lno_t *) (solution->getPermutationRCP().getRawPtr());
00095 
00096   // Get local graph.
00097   ArrayView<const lno_t> edgeIds;
00098   ArrayView<const lno_t> offsets;
00099   ArrayView<StridedData<lno_t, scalar_t> > wgts;
00100   model->getLocalEdgeList(edgeIds, offsets, wgts);
00101 
00102   // Store degrees together with index so we can sort.
00103   std::vector<std::pair<lno_t, lno_t> >  degrees(nVtx);
00104   for (lno_t i=0; i<nVtx; i++){
00105     degrees[i].first  = offsets[i+1] - offsets[i];
00106     degrees[i].second = i;
00107   }
00108 
00109   // Sort degrees.
00110   std::sort(degrees.begin(), degrees.end(), comp);
00111 
00112   // Copy permuted indices to perm.
00113   for (lno_t i=0; i<nVtx; i++){
00114     perm[i] = degrees[i].second;
00115   }
00116 
00117   return ierr;
00118 #endif // INCLUDE_ZOLTAN2_EXPERIMENTAL
00119 }
00120 
00121 }
00122 #endif