[NL] Add shape matrices for point elements.

NumLib/Fem/ShapeFunction/ShapePoint1-impl.h

+/**
+ * \copyright
+ * Copyright (c) 2012-2015, OpenGeoSys Community (http://www.opengeosys.org)
+ *            Distributed under a Modified BSD License.
+ *              See accompanying file LICENSE.txt or
+ *              http://www.opengeosys.org/project/license
+ *
+ */
+
+namespace NumLib
+{
+
+template <class T_X, class T_N>
+void ShapePoint1::computeShapeFunction(const T_X& /*r*/, T_N& N)
+{
+	N[0] = 1;
+}
+
+}

NumLib/Fem/ShapeFunction/ShapePoint1.h

+/**
+ * \copyright
+ * Copyright (c) 2012-2015, OpenGeoSys Community (http://www.opengeosys.org)
+ *            Distributed under a Modified BSD License.
+ *              See accompanying file LICENSE.txt or
+ *              http://www.opengeosys.org/project/license
+ *
+ */
+
+#ifndef SHAPEPOINT1_H_
+#define SHAPEPOINT1_H_
+
+#include "MeshLib/Elements/Point.h"
+
+namespace NumLib
+{
+///  Shape function for a point element in natural coordinates.
+class ShapePoint1
+{
+public:
+	/// Evaluate the shape function at the given point
+	///
+	/// @param [in]  r    point coordinates
+	/// @param [out] N   a vector of calculated shape function.
+	template <class T_X, class T_N>
+	static void computeShapeFunction(const T_X& r, T_N& N);
+
+	using MeshElement = MeshLib::Point;
+	static const std::size_t DIM = MeshElement::dimension;
+	static const std::size_t NPOINTS = MeshElement::n_all_nodes;
+};
+}
+
+#include "ShapePoint1-impl.h"
+
+#endif  // SHAPEPOINT1_H_