Adding upstream version 1.3.upstream/1.3upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 138 insertions, 0 deletions

diff --git a/include/2geom/numeric/linear_system.h b/include/2geom/numeric/linear_system.h
new file mode 100644
index 0000000..f793e20
--- /dev/null
+++ b/include/2geom/numeric/linear_system.h
@@ -0,0 +1,138 @@
+/*
+ * LinearSystem class wraps some gsl routines for solving linear systems
+ *
+ * Authors:
+ * 		Marco Cecchetti <mrcekets at gmail.com>
+ * 
+ * Copyright 2008  authors
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it either under the terms of the GNU Lesser General Public
+ * License version 2.1 as published by the Free Software Foundation
+ * (the "LGPL") or, at your option, under the terms of the Mozilla
+ * Public License Version 1.1 (the "MPL"). If you do not alter this
+ * notice, a recipient may use your version of this file under either
+ * the MPL or the LGPL.
+ *
+ * You should have received a copy of the LGPL along with this library
+ * in the file COPYING-LGPL-2.1; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * You should have received a copy of the MPL along with this library
+ * in the file COPYING-MPL-1.1
+ *
+ * The contents of this file are subject to the Mozilla Public License
+ * Version 1.1 (the "License"); you may not use this file except in
+ * compliance with the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
+ * OF ANY KIND, either express or implied. See the LGPL or the MPL for
+ * the specific language governing rights and limitations.
+ */
+
+
+#ifndef _NL_LINEAR_SYSTEM_H_
+#define _NL_LINEAR_SYSTEM_H_
+
+
+#include <cassert>
+
+#include <gsl/gsl_linalg.h>
+
+#include <2geom/numeric/matrix.h>
+#include <2geom/numeric/vector.h>
+
+
+namespace Geom { namespace NL {
+
+
+class LinearSystem
+{
+public:
+	LinearSystem(MatrixView & _matrix, VectorView & _vector)
+		: m_matrix(_matrix), m_vector(_vector), m_solution(_matrix.columns())
+	{
+	}
+	
+	LinearSystem(Matrix & _matrix, Vector & _vector)
+		: m_matrix(_matrix), m_vector(_vector), m_solution(_matrix.columns())
+	{
+	}
+	
+	const Vector & LU_solve()
+	{
+		assert( matrix().rows() == matrix().columns() 
+				&& matrix().rows() == vector().size() );
+		int s;
+		gsl_permutation * p = gsl_permutation_alloc(matrix().rows());
+		gsl_linalg_LU_decomp (matrix().get_gsl_matrix(), p, &s);
+		gsl_linalg_LU_solve( matrix().get_gsl_matrix(), 
+							 p, 
+				             vector().get_gsl_vector(), 
+				             m_solution.get_gsl_vector()
+				           );
+		gsl_permutation_free(p);
+		return solution();
+	}
+	
+	const Vector & SV_solve()
+	{
+		assert( matrix().rows() >= matrix().columns()
+				&& matrix().rows() == vector().size() );
+		
+		gsl_matrix* U = matrix().get_gsl_matrix();
+		gsl_matrix* V = gsl_matrix_alloc(matrix().columns(), matrix().columns());
+		gsl_vector* S = gsl_vector_alloc(matrix().columns());
+		gsl_vector* work = gsl_vector_alloc(matrix().columns());
+		
+		gsl_linalg_SV_decomp( U, V, S, work );
+		
+		gsl_vector* b = vector().get_gsl_vector();
+		gsl_vector* x = m_solution.get_gsl_vector();
+		
+		gsl_linalg_SV_solve( U, V, S, b, x);
+		
+		gsl_matrix_free(V);
+		gsl_vector_free(S);
+		gsl_vector_free(work);
+		
+		return solution();			  
+	}
+	
+	MatrixView & matrix()
+	{
+		return m_matrix;
+	}
+	
+	VectorView & vector()
+	{
+		return m_vector;
+	}
+	
+	const Vector & solution() const
+	{
+		return m_solution;
+	}
+	
+private:
+	MatrixView m_matrix;
+	VectorView m_vector;
+	Vector m_solution;
+};
+
+
+} } // end namespaces
+
+
+#endif /*_NL_LINEAR_SYSTEM_H_*/
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :