From: David Wells <wellsd2@rpi.edu>
Date: Tue, 20 Oct 2015 15:12:15 +0000 (-0400)
Subject: Remove duplicate copies of MappingQ1 functions.
X-Git-Tag: v8.4.0-rc2~300^2~1
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=288b6f2961bf8d1e8ce290c50bcb0c9c4b5fa8e9;p=dealii.git

Remove duplicate copies of MappingQ1 functions.

During refactoring we ended up with two nearly identical copies of the
same three functions.
---

diff --git a/source/fe/mapping_q_generic.cc b/source/fe/mapping_q_generic.cc
index b2cf9d06bb..91db94cfc0 100644
--- a/source/fe/mapping_q_generic.cc
+++ b/source/fe/mapping_q_generic.cc
@@ -201,128 +201,6 @@ namespace internal
 {
   namespace MappingQGeneric
   {
-    // These are left as templates on the spatial dimension (even though dim
-    // == spacedim must be true for them to make sense) because templates are
-    // expanded before the compiler eliminates code due to the 'if (dim ==
-    // spacedim)' statement (see the body of the general
-    // transform_real_to_unit_cell).
-    template<int spacedim>
-    Point<1>
-    transform_real_to_unit_cell
-    (const std_cxx11::array<Point<spacedim>, GeometryInfo<1>::vertices_per_cell> &vertices,
-     const Point<spacedim> &p)
-    {
-      Assert(spacedim == 1, ExcInternalError());
-      return Point<1>((p[0] - vertices[0](0))/(vertices[1](0) - vertices[0](0)));
-    }
-
-
-
-    template<int spacedim>
-    Point<2>
-    transform_real_to_unit_cell
-    (const std_cxx11::array<Point<spacedim>, GeometryInfo<2>::vertices_per_cell> &vertices,
-     const Point<spacedim> &p)
-    {
-      Assert(spacedim == 2, ExcInternalError());
-      const double x = p(0);
-      const double y = p(1);
-
-      const double x0 = vertices[0](0);
-      const double x1 = vertices[1](0);
-      const double x2 = vertices[2](0);
-      const double x3 = vertices[3](0);
-
-      const double y0 = vertices[0](1);
-      const double y1 = vertices[1](1);
-      const double y2 = vertices[2](1);
-      const double y3 = vertices[3](1);
-
-      const double a = (x1 - x3)*(y0 - y2) - (x0 - x2)*(y1 - y3);
-      const double b = -(x0 - x1 - x2 + x3)*y + (x - 2*x1 + x3)*y0 - (x - 2*x0 + x2)*y1
-                       - (x - x1)*y2 + (x - x0)*y3;
-      const double c = (x0 - x1)*y - (x - x1)*y0 + (x - x0)*y1;
-
-      const double discriminant = b*b - 4*a*c;
-      // fast exit if the point is not in the cell (this is the only case
-      // where the discriminant is negative)
-      if (discriminant < 0.0)
-        {
-          return Point<2>(2, 2);
-        }
-
-      double eta1;
-      double eta2;
-      // special case #1: if a is zero, then use the linear formula
-      if (a == 0.0 && b != 0.0)
-        {
-          eta1 = -c/b;
-          eta2 = -c/b;
-        }
-      // special case #2: if c is very small or the square root of the
-      // discriminant is nearly b.
-      else if (std::abs(c) < 1e-12*std::abs(b)
-               || std::abs(std::sqrt(discriminant) - b) <= 1e-14*std::abs(b))
-        {
-          eta1 = (-b - std::sqrt(discriminant)) / (2*a);
-          eta2 = (-b + std::sqrt(discriminant)) / (2*a);
-        }
-      // finally, use the numerically stable version of the quadratic formula:
-      else
-        {
-          eta1 = 2*c / (-b - std::sqrt(discriminant));
-          eta2 = 2*c / (-b + std::sqrt(discriminant));
-        }
-      // pick the one closer to the center of the cell.
-      const double eta = (std::abs(eta1 - 0.5) < std::abs(eta2 - 0.5)) ? eta1 : eta2;
-
-      /*
-       * There are two ways to compute xi from eta, but either one may have a
-       * zero denominator.
-       */
-      const double subexpr0 = -eta*x2 + x0*(eta - 1);
-      const double xi_denominator0 = eta*x3 - x1*(eta - 1) + subexpr0;
-      const double max_x = std::max(std::max(std::abs(x0), std::abs(x1)),
-                                    std::max(std::abs(x2), std::abs(x3)));
-
-      if (std::abs(xi_denominator0) > 1e-10*max_x)
-        {
-          const double xi = (x + subexpr0)/xi_denominator0;
-          return Point<2>(xi, eta);
-        }
-      else
-        {
-          const double max_y = std::max(std::max(std::abs(y0), std::abs(y1)),
-                                        std::max(std::abs(y2), std::abs(y3)));
-          const double subexpr1 = -eta*y2 + y0*(eta - 1);
-          const double xi_denominator1 = eta*y3 - y1*(eta - 1) + subexpr1;
-          if (std::abs(xi_denominator1) > 1e-10*max_y)
-            {
-              const double xi = (subexpr1 + y)/xi_denominator1;
-              return Point<2>(xi, eta);
-            }
-          else // give up and try Newton iteration
-            {
-              return Point<2>(2, 2);
-            }
-        }
-    }
-
-
-
-    template<int spacedim>
-    Point<3>
-    transform_real_to_unit_cell
-    (const std_cxx11::array<Point<spacedim>, GeometryInfo<3>::vertices_per_cell> &/*vertices*/,
-     const Point<spacedim> &/*p*/)
-    {
-      // It should not be possible to get here
-      Assert(false, ExcInternalError());
-      return Point<3>();
-    }
-
-
-
     template <int spacedim>
     void
     compute_shape_function_values (const unsigned int            n_shape_functions,