From 0984241bfffc1cd004c1533e4a5b0d869d5725b1 Mon Sep 17 00:00:00 2001
From: FyloZ <fylozdev@gmail.com>
Date: Tue, 12 Mar 2024 13:35:40 -0400
Subject: [PATCH] Graph color solver

---
 labo_physique/Solvers.h | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/labo_physique/Solvers.h b/labo_physique/Solvers.h
index 3815509..062f75a 100644
--- a/labo_physique/Solvers.h
+++ b/labo_physique/Solvers.h
@@ -79,7 +79,42 @@ namespace gti320 {
         //
         // Implémenter la méthode de Gauss-Seidel avec coloration de graphe.
         // Les partitions avec l'index de chaque particule sont stockées dans la table des tables, P.
+        int n = b.size();
 
+        x.resize(n);
+        x.setZero();
+
+        bool converged = false;
+        int k = 0;
+
+        do {
+            Vector<float, Dynamic> nx = x;
+            for (const auto &indices: P) {
+#pragma omp parallel for
+                for (int i = 0; i < indices.size(); i++) {
+                    nx(i) = b(i);
+
+                    for (int j = 0; j < i; j++) {
+                        nx(i) = nx(i) - A(i, j) * nx(j);
+                    }
+
+                    for (int j = i + 1; j < n; j++) {
+                        nx(i) = nx(i) - A(i, j) * x(j);
+                    }
+
+                    nx(i) = nx(i) / A(i, i);
+                }
+            }
+
+            k++;
+            Vector<float, Dynamic> r = A * x - b;
+
+            converged = k >= maxIter ||
+                        (nx - x).norm() / nx.norm() < tau ||
+                        r.norm() / b.norm() < eps;
+
+            x = nx;
+        } while (!converged);
     }
 
     /**