Add Unittest for Bernstein evalCoef Routine

tests/CMakeLists.txt

@@ -5,6 +5,7 @@ set(UNITTESTS
 		test_Bezierextraction
 		test_SurfacePointUpdate
 		test_Spline
+		test_Bernstein
 		test_Projector
 		test_Glue
 		test_TangentialTrace

tests/test_Bernstein.cpp

@@ -0,0 +1,45 @@
+// This file is part of Bembel, the higher order C++ boundary element library.
+//
+// Copyright (C) 2024 see <http://www.bembel.eu>
+//
+// It was written as part of a cooperation of J. Doelz, H. Harbrecht, S. Kurz,
+// M. Multerer, S. Schoeps, and F. Wolf at Technische Universitaet Darmstadt,
+// Universitaet Basel, and Universita della Svizzera italiana, Lugano. This
+// source code is subject to the GNU General Public License version 3 and
+// provided WITHOUT ANY WARRANTY, see <http://www.bembel.eu> for further
+// information.
+
+#include <Bembel/Spline>
+
+#include "tests/Test.hpp"
+
+int main() {
+  using namespace Bembel;
+
+  // We test the Bernstein with given control points against the deBoor code
+  constexpr int P = Bembel::Constants::MaxP;
+  double* coefs = new double[P + 1];
+
+  for (int i = 0; i < P + 1; ++i) {
+    coefs[i] = (i + 1) / static_cast<double>(P + 1);
+  }
+
+  Eigen::Map<Eigen::MatrixXd> coefs_vector(coefs, 1, P + 1);
+
+  for (int p = 0; p < Bembel::Constants::MaxP; ++p) {
+    for (auto x : Test::Constants::eq_points) {
+      double result1 = Basis::ShapeFunctionHandler::evalCoef(p, coefs, x);
+
+      std::vector<double> v = {x};
+      double result2 =
+          Spl::DeBoor(Eigen::MatrixXd(coefs_vector.leftCols(p + 1)),
+                      Spl::MakeBezierKnotVector(p + 1), v)(0);
+
+      BEMBEL_TEST_IF(std::abs(result1 - result2) <
+                     Test::Constants::coefficient_accuracy);
+    }
+  }
+
+  delete[] coefs;
+  return 0;
+}