introduce RowMajorSparsity type

MathLib/LinAlg/Sparse/Sparsity.h

+/**
+ * Copyright (c) 2012, OpenGeoSys Community (http://www.opengeosys.org)
+ *            Distributed under a Modified BSD License.
+ *              See accompanying file LICENSE.txt or
+ *              http://www.opengeosys.org/project/license
+ *
+ *
+ * \file Sparsity.h
+ *
+ * Created on 2012-06-25 by Norihiro Watanabe
+ */
+
+#ifndef SPARSITY_H_
+#define SPARSITY_H_
+
+#include <vector>
+#include <set>
+
+namespace MathLib 
+{
+
+/**
+ * \brief Row-major sparse pattern
+ */
+typedef std::vector<std::set<std::size_t> > RowMajorSparsity;
+
+/**
+ * convert a row-major sparsity to CRS data
+ *
+ * @tparam INTTYPE              index type
+ * @param row_major_entries     Row-major sparse pattern
+ * @param n_rows                The number of rows
+ * @param row_ptr               Pointer to row index
+ * @param col_idx               Pointer to column index
+ * @param nonzero               The number of non-zero entries
+ * @param data                  Pointer to non-zero values
+ */
+template<class INTTYPE>
+void convertRowMajorSparsityToCRS(const RowMajorSparsity &row_major_entries, std::size_t &n_rows, INTTYPE* &row_ptr, INTTYPE* &col_idx, std::size_t &nonzero, double* &data);
+
+} // end namespace MathLib
+
+#include "Sparsity.tpp"
+
+#endif // SPARSITY_H_

MathLib/LinAlg/Sparse/Sparsity.tpp

+/**
+ * Copyright (c) 2012, OpenGeoSys Community (http://www.opengeosys.org)
+ *            Distributed under a Modified BSD License.
+ *              See accompanying file LICENSE.txt or
+ *              http://www.opengeosys.org/project/license
+ *
+ *
+ * \file Sparsity.tpp
+ *
+ * Created on 2012-12-03 by Norihiro Watanabe
+ */
+
+#ifndef SPARSITY_TPP_
+#define SPARSITY_TPP_
+
+#include <cassert>
+
+namespace MathLib 
+{
+
+template<class INTTYPE>
+void convertRowMajorSparsityToCRS(const RowMajorSparsity &row_major_entries, std::size_t &n_rows, INTTYPE* &row_ptr, INTTYPE* &col_idx, std::size_t &nonzero, double* &data)
+{
+    n_rows = row_major_entries.size();
+    assert(n_rows > 0);
+    if (n_rows==0) return;
+
+    // get the number of nonzero entries and store the locations in the nonzero
+    // vector that start a row
+    nonzero = 0;
+    row_ptr = new INTTYPE[n_rows+1];
+    for (std::size_t i=0; i<n_rows; i++) {
+        row_ptr[i] = nonzero;         // starting point of the row
+        nonzero += row_major_entries[i].size(); // entries at the i th row
+    }
+    row_ptr[n_rows] = nonzero;
+
+    // store column indexes of nonzero entries
+    col_idx = new INTTYPE[nonzero];
+    size_t cnt_entries = 0;
+    for (std::size_t i=0; i<n_rows; i++) {
+        const std::set<std::size_t> &setConnection = row_major_entries[i];
+        for (std::set<std::size_t>::iterator it=setConnection.begin(); it!=setConnection.end(); ++it) {
+            col_idx[cnt_entries++] = *it;
+        }
+    }
+
+    // allocate memory for nonzero entries
+    data = new double[nonzero];
+    for (std::size_t i=0; i<nonzero; i++)
+        data[i] = .0;
+}
+
+} // end namespace MathLib
+
+#endif // SPARSITY_TPP_