summaryrefslogtreecommitdiffstats
path: root/src/3rdparty/adaptagrams/libcola/sparse_matrix.h
diff options
context:
space:
mode:
Diffstat (limited to 'src/3rdparty/adaptagrams/libcola/sparse_matrix.h')
-rw-r--r--src/3rdparty/adaptagrams/libcola/sparse_matrix.h140
1 files changed, 140 insertions, 0 deletions
diff --git a/src/3rdparty/adaptagrams/libcola/sparse_matrix.h b/src/3rdparty/adaptagrams/libcola/sparse_matrix.h
new file mode 100644
index 0000000..f4ec858
--- /dev/null
+++ b/src/3rdparty/adaptagrams/libcola/sparse_matrix.h
@@ -0,0 +1,140 @@
+/*
+ * vim: ts=4 sw=4 et tw=0 wm=0
+ *
+ * libcola - A library providing force-directed network layout using the
+ * stress-majorization method subject to separation constraints.
+ *
+ * Copyright (C) 2006-2008 Monash University
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ * See the file LICENSE.LGPL distributed with the library.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * Author(s): Tim Dwyer
+*/
+
+/*
+ * Yale Sparse Matrix implementation (from Wikipedia definition).
+ * It stores an initial sparse n×n matrix M in row form using three arrays, A,
+ * IA, JA. NZ denotes the number of nonzero entries in matrix M. The array A
+ * then is of length NZ and holds all nonzero entries of M. The array IA stores
+ * at IA(i) the position of the first element of row i in the sparse array A.
+ * The length of row i is determined by IA(i+1) - IA(i). Therefore IA needs to
+ * be of length N + 1. In array JA, the column index of the element A(j) is
+ * stored. JA is of length NZ.
+ */
+#ifndef _SPARSE_MATRIX_H
+#define _SPARSE_MATRIX_H
+
+#include <valarray>
+#include <map>
+#include <cstdio>
+
+#include "libvpsc/assertions.h"
+
+namespace cola {
+struct SparseMap {
+ SparseMap(unsigned n = 0) : n(n) {};
+ unsigned n;
+ typedef std::pair<unsigned, unsigned> SparseIndex;
+ typedef std::map<SparseIndex,double> SparseLookup;
+ typedef SparseLookup::const_iterator ConstIt;
+ SparseLookup lookup;
+ double& operator[](const SparseIndex& k) {
+ return lookup[k];
+ }
+ double& operator()(const unsigned i, const unsigned j) {
+ return lookup[std::make_pair(i,j)];
+ }
+ double getIJ(const unsigned i, const unsigned j) const {
+ COLA_ASSERT(i<n);
+ COLA_ASSERT(j<n);
+ ConstIt v=lookup.find(std::make_pair(i,j));
+ if(v!=lookup.end()) {
+ return v->second;
+ }
+ return 0;
+ }
+ size_t nonZeroCount() const {
+ return lookup.size();
+ }
+ void resize(unsigned n) {
+ this->n = n;
+ }
+ void clear() {
+ lookup.clear();
+ }
+};
+/*
+ * Yale Sparse Matrix implementation (from Wikipedia definition).
+ * It stores an initial sparse n×n matrix M in row form using three arrays, A,
+ * IA, JA. NZ denotes the number of nonzero entries in matrix M. The array A
+ * then is of length NZ and holds all nonzero entries of M. The array IA stores
+ * at IA(i) the position of the first element of row i in the sparse array A.
+ * The length of row i is determined by IA(i+1) - IA(i). Therefore IA needs to
+ * be of length N + 1. In array JA, the column index of the element A(j) is
+ * stored. JA is of length NZ.
+ */
+class SparseMatrix {
+public:
+ SparseMatrix(SparseMap const & m)
+ : n(m.n), NZ((unsigned)m.nonZeroCount()), sparseMap(m),
+ A(std::valarray<double>(NZ)), IA(std::valarray<unsigned>(n+1)), JA(std::valarray<unsigned>(NZ)) {
+ unsigned cnt=0;
+ int lastrow=-1;
+ for(SparseMap::ConstIt i=m.lookup.begin(); i!=m.lookup.end(); i++) {
+ SparseMap::SparseIndex p = i->first;
+ COLA_ASSERT(p.first<n);
+ COLA_ASSERT(p.second<n);
+ A[cnt]=i->second;
+ if((int)p.first!=lastrow) {
+ for(unsigned r=lastrow+1;r<=p.first;r++) {
+ IA[r]=cnt;
+ }
+ lastrow=p.first;
+ }
+ JA[cnt]=p.second;
+ cnt++;
+ }
+ for(unsigned r=lastrow+1;r<=n;r++) {
+ IA[r]=NZ;
+ }
+ }
+ void rightMultiply(std::valarray<double> const & v, std::valarray<double> & r) const {
+ COLA_ASSERT(v.size()>=n);
+ COLA_ASSERT(r.size()>=n);
+ for(unsigned i=0;i<n;i++) {
+ r[i]=0;
+ for(unsigned j=IA[i];j<IA[i+1];j++) {
+ r[i]+=A[j]*v[JA[j]];
+ }
+ }
+ }
+ double getIJ(const unsigned i, const unsigned j) const {
+ return sparseMap.getIJ(i,j);
+ }
+ void print() const {
+ for(unsigned i=0;i<n;i++) {
+ for(unsigned j=0;j<n;j++) {
+ printf("%f ",getIJ(i,j));
+ }
+ printf("\n");
+ }
+ }
+ unsigned rowSize() const {
+ return n;
+ }
+private:
+ const unsigned n,NZ;
+ SparseMap const & sparseMap;
+ std::valarray<double> A;
+ std::valarray<unsigned> IA, JA;
+};
+} //namespace cola
+#endif /* _SPARSE_MATRIX_H */