Add test for solve_transposed_3x3()

CMakeLists_files.cmake

@@ -147,6 +147,7 @@ list (APPEND TEST_SOURCE_FILES
   tests/test_timer.cpp
   tests/test_invert.cpp
   tests/test_stoppedwells.cpp
+  tests/test_solvetransposed3x3.cpp
   tests/test_relpermdiagnostics.cpp
   tests/test_norne_pvt.cpp
   tests/test_wellprodindexcalculator.cpp

opm/simulators/linalg/bda/CPR.hpp

@@ -149,6 +149,11 @@ public:
     }
 };
 
+// solve A^T * x = b
+// A should represent a 3x3 matrix
+// x and b are vectors with 3 elements
+void solve_transposed_3x3(const double *A, const double *b, double *x);
+
 } // namespace Accelerator
 } // namespace Opm
 

tests/test_solvetransposed3x3.cpp

@@ -0,0 +1,45 @@
+/*
+  Copyright 2021 Equinor ASA
+
+  This file is part of the Open Porous Media project (OPM).
+
+  OPM is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  OPM is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with OPM.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+
+#define BOOST_TEST_MODULE SolveTransposed3x3
+#include <boost/test/unit_test.hpp>
+#include <boost/test/floating_point_comparison.hpp>
+
+#include <dune/istl/bcrsmatrix.hh>
+
+#include <opm/simulators/linalg/bda/CPR.hpp>
+
+BOOST_AUTO_TEST_CASE(testsolvetransposed3x3)
+{
+    std::vector<double> A = {-0.0973322, 1.18758e-08, -0.000185231,
+                             0.125114, 1.24919e-11, 0,
+                             -11.3854, 1.32995e-06, 0.065447};
+
+    std::vector<double> b = {0, 1, 0};
+    std::vector<double> x(3);
+    std::vector<double> x_expected = {63886256.67, 66154278, 180813.715};
+
+    Opm::Accelerator::solve_transposed_3x3(A.data(), b.data(), x.data());
+
+    for (unsigned i = 0; i < 3; ++i) {
+        BOOST_CHECK_CLOSE(x[i], x_expected[i], 1e-6);
+    }
+}