From a9eafe47d598b80cd9fd6f0c7d1f56e58ecdc626 Mon Sep 17 00:00:00 2001
From: Jaron Kent-Dobias <jaron@kent-dobias.com>
Date: Wed, 14 Sep 2022 10:47:12 +0200
Subject: Some cleanup and removal of convergence metric.

---
 rbmp.cpp | 62 ++++++++++++++++++++++++++++----------------------------------
 1 file changed, 28 insertions(+), 34 deletions(-)

diff --git a/rbmp.cpp b/rbmp.cpp
index 3a689b9..88bf18b 100644
--- a/rbmp.cpp
+++ b/rbmp.cpp
@@ -44,12 +44,6 @@ public:
     tail = &vt;
     head = &vh;
   }
-  Vertex& getHead() {
-    return *head;
-  }
-  Vertex& getTail() {
-    return *tail;
-  }
   const Vertex& getHead() const {
     return *head;
   }
@@ -64,11 +58,11 @@ public:
   double weight;
 
   Edge() : halfedges{*this, *this} {};
-  void setVertices(Vertex& vt, Vertex& vh) {
-    halfedges[0].setVertices(vt, vh);
-    halfedges[1].setVertices(vh, vt);
-    vt.addEdge(halfedges[0]);
-    vh.addEdge(halfedges[1]);
+  void setVertices(Vertex& red, Vertex& blue) {
+    halfedges[0].setVertices(red, blue);
+    halfedges[1].setVertices(blue, red);
+    red.addEdge(halfedges[0]);
+    blue.addEdge(halfedges[1]);
   }
   double belief() const {
     return halfedges[0].X + halfedges[1].X;
@@ -84,62 +78,62 @@ public:
   std::vector<Edge> edges;
 
   Graph(unsigned n, Rng& r) : vertices(2 * n * (n + 1)), edges(pow(2 * n, 2)) {
-    for (unsigned i = 0; i < vertices.size() / 2; i++) {
+    unsigned M = vertices.size() / 2;
+    for (unsigned i = 0; i < M; i++) {
       vertices[i].index = i;
       vertices[i].coordinate = {2 * (i % (n + 1)), 2 * (i / (n + 1)) + 1};
-      vertices[vertices.size() / 2 + i].index = i + vertices.size() / 2;
-      vertices[vertices.size() / 2 + i].coordinate = {2 * (i % n) + 1, 2 * (i / n)};
+      vertices[M + i].index = M + i;
+      vertices[M + i].coordinate = {2 * (i % n) + 1, 2 * (i / n)};
     }
     for (unsigned i = 0; i < edges.size(); i++) {
-      Vertex& blueVertex = vertices[vertices.size() / 2 + (i % (2 * n)) / 2 + n * (((i + 2*n) / 4) / n)];
-      Vertex& redVertex = vertices[(1+(i % (2 * n))) / 2 + (n + 1) * ((i / 4) / (n))];
+      Vertex& redVertex = vertices[(1 + (i % (2 * n))) / 2 + (n + 1) * ((i / 4) / n)];
+      Vertex& blueVertex = vertices[M + (i % (2 * n)) / 2 + n * (((i + 2 * n) / 4) / n)];
       edges[i].setVertices(redVertex, blueVertex);
       edges[i].weight = r.variate<double, std::exponential_distribution>(1);
     }
   }
 
-  double propagateBeliefs() {
+  void propagateBeliefs() {
     for (Edge& e : edges) {
-      for (HalfEdge& he : e.halfedges) {
+      for (HalfEdge& h : e.halfedges) {
         double Xt = std::numeric_limits<double>::infinity();
-        for (const HalfEdge& en : he.getHead().neighbors) {
-          if (he.getTail().index != en.getHead().index) {
-            Xt = std::min(en.edge.weight - en.oldX, Xt);
+        for (const HalfEdge& hn : h.getHead().neighbors) {
+          if (h.getTail().index != hn.getHead().index) {
+            Xt = std::min(hn.edge.weight - hn.oldX, Xt);
           }
         }
-        he.X = Xt;
+        h.X = Xt;
       }
     }
 
-    double ΔX = std::numeric_limits<double>::infinity();
-
     for (Edge& e : edges) {
-      ΔX = std::min(ΔX, e.belief());
-
       for (HalfEdge& he : e.halfedges) {
         he.oldX = he.X;
       }
     }
-
-    return ΔX;
   }
 };
 
 int main() {
+  unsigned n = 100;
+  unsigned steps = 1e5;
   Rng r;
-  Graph G(1000, r);
-
-  double Δx = 0;
+  Graph G(n, r);
 
-  while (Δx < 1) {
-    Δx = G.propagateBeliefs();
+  for (unsigned i = 0; i < steps; i++) {
+    G.propagateBeliefs();
   }
 
   for (unsigned i = 0; i < G.edges.size(); i++) {
     if (G.edges[i].active()) {
-      std::cout << G.edges[i].halfedges[0].getTail().coordinate[0] << " " << G.edges[i].halfedges[0].getTail().coordinate[1] << " " << G.edges[i].halfedges[0].getHead().coordinate[0] << " " << G.edges[i].halfedges[0].getHead().coordinate[1] << std::endl;
+      std::cout
+        << G.edges[i].halfedges[0].getTail().coordinate[0] << " "
+        << G.edges[i].halfedges[0].getTail().coordinate[1] << " "
+        << G.edges[i].halfedges[0].getHead().coordinate[0] << " "
+        << G.edges[i].halfedges[0].getHead().coordinate[1] << std::endl;
     }
   }
 
+  return 0;
 }
 
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