feat: added task solution for third special lab

Author: Krasnovvvvv

CMakeLists.txt

@@ -42,6 +42,6 @@ function(add_lab lab_number)
 endfunction()
 
 
-add_lab(7)
+add_lab(3 ON)
 
 

src/Labs/Special/Lab3/Task1.cpp

@@ -0,0 +1,98 @@
+#include <cmath>
+#include <vector>
+#include <memory>
+#include <iostream>
+
+// PDE solvers
+#include "Labs/Special/Lab3/ConvectionSolvers/FTCSSolver.h"
+#include "Labs/Special/Lab3/ConvectionSolvers/LaxWendroffSolver.h"
+#include "Labs/Special/Lab3/ConvectionSolvers/RichtmyerSolver.h"
+#include "Labs/Special/Lab3/ConvectionSolvers/MacCormackSolver.h"
+#include "Labs/Special/Lab3/ConvectionSolvers/Upwind1Solver.h"
+#include "Labs/Special/Lab3/ConvectionSolvers/Upwind2Solver.h"
+#include "Labs/Special/Lab3/ConvectionSolvers/BTCSSolver.h"
+
+// Task
+#include "Labs/Special/Lab3/Tasks/ConvectionTask.h"
+
+// Linear solver for BTCS
+#include "Labs/Lab1/SLAESolvers/ThomasSolver.h"
+
+int main() {
+    using namespace special;
+
+    const double xL = 0.0;
+    const double xR = 1.0;
+    const std::size_t Nx = 201;      // число узлов по x
+
+    const double t0 = 0.0;
+    const double tN = 10.0;
+
+    std::vector<double> outputTimes{0.1, 0.5, 1.0, 5.0, 10.0};
+
+    // скорость переноса (можно менять, но c = u*dt/dx будет подбираться ниже)
+    const double u = 0.1;
+
+    auto phi = [](double x) {
+        return std::cos(M_PI * x / 2.0);
+    };
+
+    auto exact_solution = [=](double x, double t) {
+        double arg = x - u * t;
+        return std::cos(M_PI * arg / 2.0);
+    };
+
+    auto leftBC  = [=](double t) { return exact_solution(xL, t); };
+    auto rightBC = [=](double t) { return exact_solution(xR, t); };
+
+    Plotter plotter;
+
+    ThomasSolver linearSolver;
+    BTCSSolver btcsSolver(linearSolver);
+
+    FTCSSolver        ftcsSolver;
+    LaxWendroffSolver lwSolver;
+    RichtmyerSolver   richtSolver;
+    MacCormackSolver  macSolver;
+    Upwind1Solver     up1Solver;
+    Upwind2Solver     up2Solver;
+
+    std::vector<IConvectionSolver*> solvers = {
+        &ftcsSolver,
+        &lwSolver,
+        &richtSolver,
+        &macSolver,
+        &up1Solver,
+        &up2Solver,
+        &btcsSolver
+    };
+
+    std::vector<double> c_values{0.1, 0.5, 1.0};
+
+    for (double c : c_values) {
+        double dx = (xR - xL) / (Nx - 1);
+        double dt = c * dx / u;
+
+        std::cout << "\n=============================\n";
+        std::cout << "Convection number c = " << c
+                  << ", dt = " << dt << "\n";
+
+        ConvectionTaskParams params;
+        params.xL = xL;
+        params.xR = xR;
+        params.Nx = Nx;
+        params.t0 = t0;
+        params.tN = tN;
+        params.dt = dt;
+        params.convectionVelocity = u;
+        params.u0    = phi;
+        params.exact = exact_solution;
+        params.leftBC  = leftBC;
+        params.rightBC = rightBC;
+
+        for (IConvectionSolver* s : solvers) {
+            ConvectionTask task(*s, &plotter, "x", "U");
+            task.run(params, outputTimes);
+        }
+    }
+}