1 files changed, 41 insertions, 0 deletions
diff --git a/hard_spheres.cpp b/hard_spheres.cpp
new file mode 100644
index 0000000..b53f7cf
--- /dev/null
+++ b/hard_spheres.cpp
@@ -0,0 +1,41 @@
+#include "animation.hpp"
+
+int main(int argc, char* argv[]) {
+  unsigned N = 1200;
+  double R = 0.021;
+  double ε = 0.01;
+  unsigned steps = 1e6;
+
+  initializeAnimation(argc, argv);
+
+  Rng r;
+
+  Model<2, HardSphere<2>> m(N, 2 * R);
+
+  for (unsigned i = 0; i < N; i++) {
+    Position<2> x = {r.uniform(0.0, 1.0), r.uniform(0.0, 1.0)};
+    double rad = pow(r.uniform(pow(2.219, -2), 1.0), -0.5) * R / 2.219;
+    m.insert(HardSphere<2>(x, rad));
+  }
+
+  for (unsigned i = 0; i < steps * N; i++) {
+    HardSphere<2>& s = r.pick(m.particles);
+    Vector<2> Δx;
+    for (double& Δxi : Δx) {
+      Δxi = r.variate<double, std::normal_distribution>(0, ε);
+    }
+
+    m.metropolis(1, s, Δx, r);
+
+    HardSphere<2>& s1 = r.pick(m.particles);
+    HardSphere<2>& s2 = r.pick(m.particles);
+    
+    m.swap(1, s1, s2, r);
+
+    if (i % (N * 3) == 0) {
+      draw(m);
+    }
+  }
+
+  return 0;
+}