Added 2D example with constant bc on left side

app/CMakeLists.txt

@@ -6,3 +6,6 @@ target_link_libraries(2D PUBLIC diffusion)
 
 add_executable(Comp2D main_2D_mdl.cpp)
 target_link_libraries(Comp2D PUBLIC diffusion)
+
+add_executable(Const2D main_2D_const.cpp)
+target_link_libraries(Const2D PUBLIC diffusion)

app/main_2D_const.cpp

@@ -0,0 +1,57 @@
+#include <algorithm> // for copy, max
+#include <cmath>
+#include <diffusion/BTCSDiffusion.hpp>
+#include <diffusion/BoundaryCondition.hpp>
+#include <iomanip>
+#include <iostream> // for std
+#include <vector>   // for vector
+using namespace std;
+
+using namespace Diffusion;
+
+int main(int argc, char *argv[]) {
+
+  // dimension of grid
+  int dim = 2;
+
+  int n = 5;
+  int m = 5;
+
+  // create input + diffusion coefficients for each grid cell
+  std::vector<double> alpha(n * m, 1 * pow(10, -1));
+  std::vector<double> field(n * m, 1 * std::pow(10, -6));
+  std::vector<boundary_condition> bc((n + 2) * (m + 2), {0, 0});
+
+  // create instance of diffusion module
+  BTCSDiffusion diffu(dim);
+
+  diffu.setXDimensions(1, n);
+  diffu.setYDimensions(1, m);
+
+  for (int i = 1; i <= n; i++) {
+    bc[(n + 2) * i] = {Diffusion::BC_CONSTANT, 5 * std::pow(10, -6)};
+  }
+  // set timestep for simulation to 1 second
+  diffu.setTimestep(1.);
+
+  cout << setprecision(12);
+
+  for (int t = 0; t < 10; t++) {
+    diffu.simulate(field.data(), alpha.data(), bc.data());
+
+    cout << "Iteration: " << t << "\n\n";
+
+    // iterate through rows
+    for (int i = 0; i < m; i++) {
+      // iterate through columns
+      for (int j = 0; j < n; j++) {
+        cout << left << std::setw(20) << field[i * n + j];
+      }
+      cout << "\n";
+    }
+
+    cout << "\n" << endl;
+  }
+
+  return 0;
+}