tug: cpp: Remove alternative solver

src/benchmarks/tug/cpp/include/tug/Core/BTCS.hpp

@@ -123,8 +123,6 @@ createCoeffMatrix(const RowMajMat<T> &alpha,
     }
   }
 
-  cm.makeCompressed(); // important for Eigen solver
-
   return cm;
 }
 
@@ -244,20 +242,6 @@ createSolutionVector(const RowMajMat<T> &concentrations,
   return sv;
 }
 
-// solver for linear equation system; A corresponds to coefficient matrix,
-// b to the solution vector
-// use of EigenLU solver
-template <class T>
-static Eigen::VectorX<T> EigenLUAlgorithm(Eigen::SparseMatrix<T> &A,
-                                          Eigen::VectorX<T> &b) {
-
-  Eigen::SparseLU<Eigen::SparseMatrix<T>> solver;
-  solver.analyzePattern(A);
-  solver.factorize(A);
-
-  return solver.solve(b);
-}
-
 // solver for linear equation system; A corresponds to coefficient matrix,
 // b to the solution vector
 // implementation of Thomas Algorithm
@@ -329,9 +313,7 @@ static Eigen::VectorX<T> ThomasAlgorithm(Eigen::SparseMatrix<T> &A,
 
 // BTCS solution for 2D grid
 template <class T>
-static void BTCS_2D(Grid<T> &grid, Boundary<T> &bc, T timestep,
-                    Eigen::VectorX<T> (*solverFunc)(Eigen::SparseMatrix<T> &A,
-                                                    Eigen::VectorX<T> &b)) {
+static void BTCS_2D(Grid<T> &grid, Boundary<T> &bc, T timestep) {
   int rowMax = grid.getRow();
   int colMax = grid.getCol();
   T sx = timestep / (2 * grid.getDeltaCol() * grid.getDeltaCol());
@@ -358,7 +340,7 @@ static void BTCS_2D(Grid<T> &grid, Boundary<T> &bc, T timestep,
     b = createSolutionVector(concentrations, alphaX, alphaY, bcLeft, bcRight,
                              bcTop, bcBottom, colMax, i, sx, sy);
 
-    concentrations_t1.row(i) = solverFunc(A, b);
+    concentrations_t1.row(i) = ThomasAlgorithm(A, b);
   }
 
   concentrations_t1.transposeInPlace();
@@ -372,18 +354,7 @@ static void BTCS_2D(Grid<T> &grid, Boundary<T> &bc, T timestep,
     b = createSolutionVector(concentrations_t1, alphaY, alphaX, bcTop, bcBottom,
                              bcLeft, bcRight, rowMax, i, sy, sx);
 
-    concentrations.col(i) = solverFunc(A, b);
-  }
-}
-
-// entry point for EigenLU solver; differentiate between 1D and 2D grid
-template <class T>
-void BTCS_LU(Grid<T> &grid, Boundary<T> &bc, T timestep) {
-  if (grid.getDim() == 2) {
-    BTCS_2D(grid, bc, timestep, EigenLUAlgorithm);
-  } else {
-    throw_invalid_argument(
-        "Error: Only 2-dimensional grids are defined!");
+    concentrations.col(i) = ThomasAlgorithm(A, b);
   }
 }
 
@@ -391,10 +362,10 @@ void BTCS_LU(Grid<T> &grid, Boundary<T> &bc, T timestep) {
 template <class T>
 void BTCS_Thomas(Grid<T> &grid, Boundary<T> &bc, T timestep) {
   if (grid.getDim() == 2) {
-    BTCS_2D(grid, bc, timestep, ThomasAlgorithm);
+    BTCS_2D(grid, bc, timestep);
   } else {
     throw_invalid_argument(
-        "Error: Only 1- and 2-dimensional grids are defined!");
+        "Error: Only 2-dimensional grids are defined!");
   }
 }
 } // namespace tug

src/benchmarks/tug/cpp/include/tug/Simulation.hpp

@@ -30,16 +30,6 @@
 
 namespace tug {
 
-/**
- * @brief Enum defining the Linear Equation solvers
- *
- */
-enum SOLVER {
-  EIGEN_LU_SOLVER,        /*!<  EigenLU solver */
-  THOMAS_ALGORITHM_SOLVER /*!< Thomas Algorithm solver; more efficient for
-                             tridiagonal matrices */
-};
-
 /**
  * @brief Enum holding different options for .csv output.
  *
@@ -69,11 +59,8 @@ enum CONSOLE_OUTPUT {
  *
  * @tparam T the type of the internal data structures for grid, boundary
  * condition and timestep
- * @tparam approach Set the SLE scheme to be used
- * @tparam solver Set the solver to be used
  */
-template <class T, APPROACH approach = BTCS_APPROACH,
-          SOLVER solver = THOMAS_ALGORITHM_SOLVER>
+template <class T>
 class Simulation {
 public:
   /**
@@ -86,7 +73,6 @@ public:
    *
    * @param grid Valid grid object
    * @param bc Valid boundary condition object
-   * @param approach Approach to solving the problem. Either FTCS or BTCS.
    */
   Simulation(Grid<T> &_grid, Boundary<T> &_bc) : grid(_grid), bc(_bc){};
 
@@ -283,18 +269,7 @@ public:
     }
 
     {
-      if constexpr (solver == EIGEN_LU_SOLVER) {
-        for (int i = 0; i < iterations; i++) {
-          if (console_output == CONSOLE_OUTPUT_VERBOSE && i > 0) {
-            printConcentrationsConsole();
-          }
-          if (csv_output >= CSV_OUTPUT_VERBOSE) {
-            printConcentrationsCSV(filename);
-          }
-
-          BTCS_LU(this->grid, this->bc, this->timestep);
-        }
-      } else if constexpr (solver == THOMAS_ALGORITHM_SOLVER) {
+      {
         for (int i = 0; i < iterations; i++) {
           if (console_output == CONSOLE_OUTPUT_VERBOSE && i > 0) {
             printConcentrationsConsole();