Add project 1 with the corresponding source code and report.

src/project1/poisson_solver.cpp

@@ -0,0 +1,56 @@
+#include <iomanip>
+#include <fstream>
+#include <cstring>
+
+#include "include/solvers.hpp"
+#include "include/helpers.hpp"
+
+using namespace std;
+
+int main(int argc, char* argv[]){
+    const int decimal_places = 14;
+    int N; // !! Number of steps between the discretization points (= N_points - 1)
+    if (argc > 1) { // Get number of steps from command line argument
+        N = atoi(argv[1]);
+    } else {
+        N = 1000;
+    }
+
+    bool output_to_file = true;
+    if (argc > 2) { // Get output preference from command line argument (use "true" or "false", default is true)
+        output_to_file = (strcmp(argv[2], "true") == 0);
+    }
+
+    const double delta_x = 1.0 / N;
+    vector<double> a(N-1, -1.0);
+    vector<double> b(N-1, 2.0);
+    vector<double> c(N-1, -1.0);
+    vector<double> g(N-1, 0.0);
+
+    cout << "Running Poisson solver with N = " << N << endl;
+    for (int i = 1; i < N; i++) {
+        double x = i * delta_x;
+        g[i-1] = delta_x * delta_x * f(x);
+    }
+
+    vector<double> solution = add_boundaries(general_algorithm(a, b, c, g));
+    vector<double> x = get_x(N);
+    vector<double> u = analytical_solution(x);
+    double max_rel_error = relative_error(solution, u);
+    cout << "Max relative error: " << max_rel_error << endl;
+
+    if (output_to_file) {
+        // Output the solution
+        string filename = "numerical_solution_" + to_string(N) + ".csv";
+        ofstream ofs(filename);
+        ofs << "x,u(x)" << endl;
+        for (int i = 0; i <= N; i++) {
+        ofs << fixed << setprecision(decimal_places) << scientific << x[i] << "," << solution[i] << endl;
+    }
+    ofs.close();
+
+    }
+
+    return 0;
+}
+