From: Daniel Arndt <arndtd@ornl.gov>
Date: Thu, 9 May 2019 03:01:58 +0000 (-0400)
Subject: Modernize step-53
X-Git-Tag: v9.1.0-rc1~109^2~1
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=34cf8d3cfa6e1ee5772ffedc0ce894edc1a82f96;p=dealii.git

Modernize step-53
---

diff --git a/examples/step-53/step-53.cc b/examples/step-53/step-53.cc
index 3e4eb436a5..602d8f6f0e 100644
--- a/examples/step-53/step-53.cc
+++ b/examples/step-53/step-53.cc
@@ -88,9 +88,7 @@ namespace Step53
   private:
     const Functions::InterpolatedUniformGridData<2> topography_data;
 
-    static std::array<std::pair<double, double>, 2> get_endpoints();
-    static std::array<unsigned int, 2>              n_intervals();
-    static std::vector<double>                      get_data();
+    static std::vector<double> get_data();
   };
 
 
@@ -112,8 +110,9 @@ namespace Step53
   // access any member variables of the class, and (ii) because they are
   // called at a time when the object is not initialized fully anyway.
   AfricaTopography::AfricaTopography()
-    : topography_data(get_endpoints(),
-                      n_intervals(),
+    : topography_data({std::make_pair(-6.983333, 11.966667),
+                       std::make_pair(25, 35.95)},
+                      {379, 219},
                       Table<2, double>(380, 220, get_data().begin()))
   {}
 
@@ -125,24 +124,6 @@ namespace Step53
   }
 
 
-  std::array<std::pair<double, double>, 2> AfricaTopography::get_endpoints()
-  {
-    std::array<std::pair<double, double>, 2> endpoints;
-    endpoints[0] = std::make_pair(-6.983333, 11.966667);
-    endpoints[1] = std::make_pair(25, 35.95);
-    return endpoints;
-  }
-
-
-  std::array<unsigned int, 2> AfricaTopography::n_intervals()
-  {
-    std::array<unsigned int, 2> endpoints;
-    endpoints[0] = 379;
-    endpoints[1] = 219;
-    return endpoints;
-  }
-
-
   // The only other function of greater interest is the <code>get_data()</code>
   // function. It returns a temporary vector that contains all 83,600 data
   // points describing the altitude and is read from the file
@@ -317,20 +298,18 @@ namespace Step53
   Point<3>
   AfricaGeometry::push_forward_topo(const Point<3> &phi_theta_d_hat) const
   {
-    const double   d_hat = phi_theta_d_hat[2];
-    const double   h = topography.value(phi_theta_d_hat[0], phi_theta_d_hat[1]);
-    const double   d = d_hat + (d_hat + 500000) / 500000 * h;
-    const Point<3> phi_theta_d(phi_theta_d_hat[0], phi_theta_d_hat[1], d);
-    return phi_theta_d;
+    const double d_hat = phi_theta_d_hat[2];
+    const double h = topography.value(phi_theta_d_hat[0], phi_theta_d_hat[1]);
+    const double d = d_hat + (d_hat + 500000) / 500000 * h;
+    return {phi_theta_d_hat[0], phi_theta_d_hat[1], d};
   }
 
   Point<3> AfricaGeometry::pull_back_topo(const Point<3> &phi_theta_d) const
   {
-    const double   d     = phi_theta_d[2];
-    const double   h     = topography.value(phi_theta_d[0], phi_theta_d[1]);
-    const double   d_hat = 500000 * (d - h) / (500000 + h);
-    const Point<3> phi_theta_d_hat(phi_theta_d[0], phi_theta_d[1], d_hat);
-    return phi_theta_d_hat;
+    const double d     = phi_theta_d[2];
+    const double h     = topography.value(phi_theta_d[0], phi_theta_d[1]);
+    const double d_hat = 500000 * (d - h) / (500000 + h);
+    return {phi_theta_d[0], phi_theta_d[1], d_hat};
   }
 
 
@@ -354,13 +333,8 @@ namespace Step53
   // a function that takes as its single argument a point in the reference
   // domain and returns the corresponding location in the domain that we
   // want to map to. This is, of course, exactly the push forward
-  // function of the geometry we use. However,
-  // <code>AfricaGeometry::push_forward()</code> requires two arguments:
-  // the <code>AfricaGeometry</code> object to work with via its implicit
-  // <code>this</code> pointer, and the point. We bind the first of these
-  // to the geometry object we have created at the top of the function
-  // and leave the second one open, obtaining the desired object to
-  // do the transformation.
+  // function of the geometry we use. We wrap it by a lambda function to
+  // obtaining the desired object required for the transformation.
   void run()
   {
     AfricaGeometry   geometry;
@@ -377,10 +351,11 @@ namespace Step53
       GridGenerator::subdivided_hyper_rectangle(
         triangulation, subdivisions, corner_points[0], corner_points[1], true);
 
-      GridTools::transform(std::bind(&AfricaGeometry::push_forward,
-                                     std::cref(geometry),
-                                     std::placeholders::_1),
-                           triangulation);
+      GridTools::transform(
+        [&geometry](const Point<3> &chart_point) {
+          return geometry.push_forward(chart_point);
+        },
+        triangulation);
     }
 
     // The next step is to explain to the triangulation to use our geometry
@@ -393,10 +368,7 @@ namespace Step53
     // mother to children, this also happens after several recursive
     // refinement steps.
     triangulation.set_manifold(0, geometry);
-    for (Triangulation<3>::active_cell_iterator cell =
-           triangulation.begin_active();
-         cell != triangulation.end();
-         ++cell)
+    for (const auto &cell : triangulation.active_cell_iterators())
       cell->set_all_manifold_ids(0);
 
     // The last step is to refine the mesh beyond its initial $1\times 2\times
@@ -412,10 +384,7 @@ namespace Step53
     // the boundaries by assigning each boundary a unique boundary indicator).
     for (unsigned int i = 0; i < 6; ++i)
       {
-        for (Triangulation<3>::active_cell_iterator cell =
-               triangulation.begin_active();
-             cell != triangulation.end();
-             ++cell)
+        for (const auto &cell : triangulation.active_cell_iterators())
           for (unsigned int f = 0; f < GeometryInfo<3>::faces_per_cell; ++f)
             if (cell->face(f)->boundary_id() == 5)
               {