Working ordering format for Metis_NodeND

gtsam/inference/MetisIndex-inl.h

@@ -0,0 +1,59 @@
+/* ----------------------------------------------------------------------------
+
+* GTSAM Copyright 2010, Georgia Tech Research Corporation,
+* Atlanta, Georgia 30332-0415
+* All Rights Reserved
+* Authors: Frank Dellaert, et al. (see THANKS for the full author list)
+
+* See LICENSE for the license information
+
+* -------------------------------------------------------------------------- */
+
+/**
+* @file    MetisIndex-inl.h
+* @author  Andrew Melim
+* @date    Oct. 10, 2014
+*/
+
+#include <gtsam/inference/MetisIndex.h>
+#include <map>
+
+namespace gtsam {
+
+    MetisIndex::~MetisIndex(){}
+
+    std::vector<int>  MetisIndex::xadj() const { return xadj_; }
+    std::vector<int>  MetisIndex::adj() const { return  adj_; }
+
+    /* ************************************************************************* */
+    template<class FACTOR>
+    void MetisIndex::augment(const FactorGraph<FACTOR>& factors)
+    {
+        std::map<int, FastSet<int> > adjMap;
+        std::map<int, FastSet<int> >::iterator adjMapIt;
+        
+        /* ********** Convert to CSR format ********** */
+        // Assuming that vertex numbering starts from 0 (C style),
+        // then the adjacency list of vertex i is stored in array adjncy
+        // starting at index xadj[i] and ending at(but not including)
+        // index xadj[i + 1](i.e., adjncy[xadj[i]] through
+        // and including adjncy[xadj[i + 1] - 1]).
+        for (size_t i = 0; i < factors.size(); i++){
+            if (factors[i])
+                BOOST_FOREACH(const Key& k1, *factors[i])
+                    BOOST_FOREACH(const Key& k2, *factors[i])
+                        if (k1 != k2)
+                            adjMap[k1].insert(adjMap[k1].end(), k2); // Insert at the end
+        }
+
+        
+        xadj_.push_back(0);// Always set the first index to zero
+        for (adjMapIt = adjMap.begin(); adjMapIt != adjMap.end(); ++adjMapIt) {
+            vector<int> temp;
+            copy(adjMapIt->second.begin(), adjMapIt->second.end(), std::back_inserter(temp));
+            adj_.insert(adj_.end(), temp.begin(), temp.end());
+            //adj_.push_back(temp);
+            xadj_.push_back(adj_.size());
+        }
+    }
+}

gtsam/inference/MetisIndex.h

@@ -0,0 +1,78 @@
+/* ----------------------------------------------------------------------------
+
+* GTSAM Copyright 2010, Georgia Tech Research Corporation,
+* Atlanta, Georgia 30332-0415
+* All Rights Reserved
+* Authors: Frank Dellaert, et al. (see THANKS for the full author list)
+
+* See LICENSE for the license information
+
+* -------------------------------------------------------------------------- */
+
+
+/**
+* @file    MetisIndex.h
+* @author  Andrew Melim
+* @date    Oct. 10, 2014
+*/
+
+#pragma once
+
+#include <vector>
+#include <boost/foreach.hpp>
+
+#include <gtsam/base/FastList.h>
+#include <gtsam/base/types.h>
+#include <gtsam/base/timing.h>
+#include <gtsam/inference/Key.h>
+
+namespace gtsam {
+    /**
+     * The MetisIndex class converts a factor graph into the Compressed Sparse Row format for use in
+     * METIS algorithms. Specifically, two vectors store the adjacency structure of the graph. It is built
+     * fromt a factor graph prior to elimination, and stores the list of factors
+     * that involve each variable.
+     * \nosubgrouping
+     */
+class GTSAM_EXPORT MetisIndex
+{
+public:
+    typedef boost::shared_ptr<MetisIndex> shared_ptr;
+
+private:
+    FastVector<int> xadj_; // Index of node's adjacency list in adj
+    FastVector<int>  adj_; // Stores ajacency lists of all nodes, appended into a single vector
+    size_t nFactors_;     // Number of factors in the original factor graph
+    size_t nValues_;      // 
+
+public:
+    /// @name Standard Constructors
+    /// @{
+
+    /** Default constructor, creates empty MetisIndex */
+    MetisIndex() : nFactors_(0), nValues_(0) {}
+
+    template<class FG>
+    MetisIndex(const FG& factorGraph) : nFactors_(0), nValues_(0) {
+        augment(factorGraph); }
+
+    ~MetisIndex();
+    /// @}
+    /// @name Advanced Interface
+    /// @{
+
+    /**
+    * Augment the variable index with new factors.  This can be used when
+    * solving problems incrementally.
+    */
+    template<class FACTOR>
+    void augment(const FactorGraph<FACTOR>& factors);
+
+    std::vector<int> xadj() const;
+    std::vector<int>  adj() const;
+
+    /// @}
+};
+}
+
+#include <gtsam/inference/MetisIndex-inl.h>

gtsam/inference/Ordering.cpp

@@ -197,10 +197,21 @@ namespace gtsam {
     return Ordering::COLAMDConstrained(variableIndex, cmember);
   }
 
+
   /* ************************************************************************* */
-  Ordering Ordering::METIS(const VariableIndex& variableIndex)
+  template<class FACTOR>
+  Ordering Ordering::METIS(const FactorGraph<FACTOR>& graph)
   {
       gttic(Ordering_METIS);
+      // First develop the adjacency matrix for the 
+      // graph as described in Section 5.5 of the METIS manual
+      // CSR Format
+      // xadj is of size n+1
+      // metis vars
+
+
+      //METIS_NodeND(graph.keys().size(), xadj, adj);
+      
   }
 
   /* ************************************************************************* */

gtsam/inference/Ordering.h

@@ -146,13 +146,15 @@ namespace gtsam {
       return Ordering(keys);
     }
 
+    /// METIS Formatting function
+    template<class FACTOR>
+    static GTSAM_EXPORT void CSRFormat(std::vector<int>& xadj, std::vector<int>& adj, const FactorGraph<FACTOR>& graph);
 
     /// Compute an ordering determined by METIS from a VariableIndex
-    static GTSAM_EXPORT Ordering METIS(const VariableIndex& variableIndex);
+    //static GTSAM_EXPORT Ordering METIS(const VariableIndex& variableIndex);
 
     template<class FACTOR>
-    static Ordering METIS(const FactorGraph<FACTOR>& graph){
+    static GTSAM_EXPORT Ordering METIS(const FactorGraph<FACTOR>& graph);
-        return METIS(VariableIndex(graph)); }
 
     /// @}
 
@@ -169,6 +171,7 @@ namespace gtsam {
     static GTSAM_EXPORT Ordering COLAMDConstrained(
       const VariableIndex& variableIndex, std::vector<int>& cmember);
 
+
     /** Serialization function */
     friend class boost::serialization::access;
     template<class ARCHIVE>

gtsam/inference/tests/testOrdering.cpp

@@ -17,6 +17,7 @@
 #include <gtsam/inference/Symbol.h>
 #include <gtsam/symbolic/SymbolicFactorGraph.h>
 #include <gtsam/inference/Ordering.h>
+#include <gtsam/inference/MetisIndex.h>
 #include <gtsam/base/TestableAssertions.h>
 #include <CppUnitLite/TestHarness.h>
 
@@ -78,7 +79,46 @@ TEST(Ordering, grouped_constrained_ordering) {
 }
 
 /* ************************************************************************* */
-TEST(Ordering, metis_ordering) {
+TEST(Ordering, csr_format) {
+
+
+    // Example in METIS manual
+    SymbolicFactorGraph sfg;
+    sfg.push_factor(0, 1);
+    sfg.push_factor(1, 2);
+    sfg.push_factor(2, 3);
+    sfg.push_factor(3, 4);
+    sfg.push_factor(5, 6);
+    sfg.push_factor(6, 7);
+    sfg.push_factor(7, 8);
+    sfg.push_factor(8, 9);
+    sfg.push_factor(10, 11);
+    sfg.push_factor(11, 12);
+    sfg.push_factor(12, 13);
+    sfg.push_factor(13, 14);
+
+    sfg.push_factor(0, 5);
+    sfg.push_factor(5, 10);
+    sfg.push_factor(1, 6);
+    sfg.push_factor(6, 11);
+    sfg.push_factor(2, 7);
+    sfg.push_factor(7, 12);
+    sfg.push_factor(3, 8);
+    sfg.push_factor(8, 13);
+    sfg.push_factor(4, 9);
+    sfg.push_factor(9, 14);
+
+    MetisIndex mi(sfg);
+
+    vector<int> xadjExpected{ 0, 2, 5, 8, 11, 13, 16, 20, 24, 28, 31, 33, 36, 39, 42, 44};
+    vector<int> adjExpected{ 1, 5, 0, 2, 6, 1, 3, 7, 2, 4, 8, 3, 9, 0, 6, 10, 1, 5, 7, 11,
+                             2, 6, 8, 12, 3, 7, 9, 13, 4, 8, 14, 5, 11, 6, 10, 12, 7, 11, 
+                             13, 8, 12, 14, 9, 13 };
+
+    EXPECT(xadjExpected  == mi.xadj());
+    EXPECT(adjExpected.size() == mi.adj().size());
+    EXPECT( adjExpected  == mi.adj());
+
 
 }