Add a testcase.

diff --git a/source/grid/tria_boundary_lib.cc b/source/grid/tria_boundary_lib.cc
index 62ee5755fa79c1f112e12fb28f2a8d5bae89b4fe..b5d3e57f06d829da23422a1556eacae7b2a5d075 100644 (file)
--- a/source/grid/tria_boundary_lib.cc
+++ b/source/grid/tria_boundary_lib.cc
@@ -489,6 +489,7 @@ normal_vector (const typename Triangulation<dim>::face_iterator &,
   for (unsigned int d=0; d<dim; ++d)
     if (d != dim-1)  // don't test the last component of the vector
       Assert (this->x_1[d] == 0., ExcNotImplemented());
+  Assert (this->x_1[dim-1] > 0, ExcNotImplemented());
 
   const double c_squared = (this->radius_1 / this->x_1[dim-1])*(this->radius_1 / this->x_1[dim-1]);
   Tensor<1,dim> normal = p;

diff --git a/tests/bits/cone_04.cc b/tests/bits/cone_04.cc
new file mode 100644 (file)
index 0000000..afe4c1b
--- /dev/null
+++ b/tests/bits/cone_04.cc
@@ -0,0 +1,87 @@
+// ---------------------------------------------------------------------
+//
+// Copyright (C) 2017 by the deal.II authors
+//
+// This file is part of the deal.II library.
+//
+// The deal.II library is free software; you can use it, 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.
+// The full text of the license can be found in the file LICENSE at
+// the top level of the deal.II distribution.
+//
+// ---------------------------------------------------------------------
+
+
+
+// check ConeBoundary<3>::normal_vector()
+
+#include "../tests.h"
+#include <deal.II/base/logstream.h>
+#include <deal.II/grid/tria_boundary_lib.h>
+
+#include <fstream>
+
+
+
+void check ()
+{
+  const Point<3> p1, p2(0,0,2);
+  const ConeBoundary<3> boundary (0, 1, p1, p2);
+
+  // test a bunch of points that are randomly chosen. first (manually)
+  // project them onto the cone (perpendicular to the z-axis) and then
+  // compute the normal vector. we test that they are correct by
+  // making sure that they (i) have unit length, (ii) are
+  // perpendicular to the tangent vector to the cone that runs from
+  // the vertex (at the origin) to the projected point, and (iii) are
+  // perpendicular to the tangent vector that is tangent to the circle
+  // the projected point sits on
+  Point<3> points[] = { Point<3>(1,1,1),
+                        Point<3>(1,0,1),
+                        Point<3>(0,1,1),
+
+                        Point<3>(1,1,1.5),
+                        Point<3>(1,0,1.5),
+                        Point<3>(0,1,1.5)
+                      };
+  for (unsigned int i=0; i<sizeof(points)/sizeof(points[0]); ++i)
+    {
+      const Point<2> radial_component (points[i][0],
+                                       points[i][1]);
+      const Point<2> projected_radial_component
+        = radial_component/radial_component.norm()
+          * (points[i][2]/2);  // radius of cone at given z
+
+      const Point<3> projected_point (projected_radial_component[0],
+                                      projected_radial_component[1],
+                                      points[i][2]);
+
+      const Tensor<1,3> tangent_1 = projected_point / projected_point.norm();
+      const Tensor<1,3> tangent_2 = cross_product_3d (tangent_1,
+                                                      Point<3>(0,0,1));
+
+      // get the normal vector and test it
+      const Tensor<1,3> normal_vector
+        = boundary.normal_vector( /* dummy= */ Triangulation<3>::face_iterator(),
+                                               projected_point);
+
+      Assert (std::fabs(normal_vector.norm()-1) < 1e-12,
+              ExcInternalError());
+      Assert (std::fabs(normal_vector * tangent_1) < 1e-12,
+              ExcInternalError());
+      Assert (std::fabs(normal_vector * tangent_2) < 1e-12,
+              ExcInternalError());
+    }
+
+  deallog << "OK" << std::endl;
+}
+
+
+int main ()
+{
+  initlog();
+
+  check ();
+}

diff --git a/tests/bits/cone_04.output b/tests/bits/cone_04.output
new file mode 100644 (file)
index 0000000..0fd8fc1
--- /dev/null
+++ b/tests/bits/cone_04.output
@@ -0,0 +1,2 @@
+
+DEAL::OK