From b117d7922e3e9760e4418541d030ed30f01a5b20 Mon Sep 17 00:00:00 2001
From: Jaron Kent-Dobias <jaron@kent-dobias.com>
Date: Mon, 18 May 2020 16:21:35 -0400
Subject: Initial commit.

---
 .gitmodules        |   6 +++
 grown_networks.cpp | 126 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 pcg-cpp            |   1 +
 randutils          |   1 +
 4 files changed, 134 insertions(+)
 create mode 100644 .gitmodules
 create mode 100644 grown_networks.cpp
 create mode 160000 pcg-cpp
 create mode 160000 randutils

diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..a14394b
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,6 @@
+[submodule "randutils"]
+	path = randutils
+	url = https://gist.github.com/imneme/540829265469e673d045
+[submodule "pcg-cpp"]
+	path = pcg-cpp
+	url = https://github.com/imneme/pcg-cpp
diff --git a/grown_networks.cpp b/grown_networks.cpp
new file mode 100644
index 0000000..bacbb71
--- /dev/null
+++ b/grown_networks.cpp
@@ -0,0 +1,126 @@
+
+#include <fstream>
+#include <random>
+#include <cinttypes>
+#include <vector>
+#include <string>
+
+#include "pcg-cpp/include/pcg_random.hpp"
+#include "randutils/randutils.hpp"
+
+#include <boost/graph/adjacency_list.hpp>
+#include <boost/graph/connected_components.hpp>
+
+using Rng = randutils::random_generator<pcg32>;
+
+typedef boost::adjacency_list<boost::listS, boost::vecS, boost::undirectedS> Graph;
+
+int main(int argc, char* argv[]) {
+  unsigned N = 10;
+  unsigned T = 1000;
+  double δ = 1.0 / 8;
+
+  int opt;
+
+  while ((opt = getopt(argc, argv, "N:T:d:")) != -1) {
+    switch (opt) {
+      case 'N':
+        N = (unsigned)atof(optarg);
+        break;
+      case 'T':
+        T = (unsigned)atof(optarg);
+        break;
+      case 'd':
+        δ = atof(optarg);
+        break;
+      default:
+        exit(1);
+    }
+  }
+
+  Rng rng;
+
+  std::uniform_real_distribution<double> dr(0.0, 1.0);
+
+  std::vector<uint64_t> ns(T);
+  std::vector<uint64_t> nS(T);
+
+  for (unsigned i = 0; i < N; i++) {
+    Graph G(T);
+
+    for (unsigned t = 0; t < T; t++) {
+      if (rng.uniform(0.0, 1.0) < δ) {
+        boost::add_edge(rng.uniform((unsigned)0, t), rng.uniform((unsigned)0, t), G);
+      }
+    }
+
+    std::vector<unsigned> components(T);
+    unsigned nc = boost::connected_components(G, &components[0]);
+
+    std::vector<unsigned> s(nc);
+
+    for (unsigned j : components) {
+      s[j]++;
+    }
+
+    unsigned j_max = 0;
+
+    for (unsigned j : s) {
+      ns[j - 1]++;
+
+      if (j > j_max) {
+        j_max = j;
+      }
+    }
+
+    nS[j_max - 1]++;
+  }
+
+  std::string filename = "ns_" + std::to_string(δ) + "_" + std::to_string(T) + ".dat";
+
+  std::ifstream outfile(filename);
+
+  std::vector<uint64_t> ns_old(T, 0);
+
+  if (outfile.is_open()) {
+    for (unsigned i = 0; i < T; i++) {
+      uint64_t num;
+      outfile >> num;
+      ns_old[i] = num;
+    }
+
+    outfile.close();
+  }
+
+  std::ofstream file_out(filename);
+
+  for (unsigned i = 0; i < T; i++) {
+    file_out <<std::fixed<< ns_old[i] + ns[i] << " ";
+  }
+
+  std::string filename_S = "nS_" + std::to_string(δ) + "_" + std::to_string(T) + ".dat";
+
+  std::ifstream outfile_S(filename_S);
+
+  std::vector<uint64_t> nS_old(T, 0);
+
+  if (outfile_S.is_open()) {
+    for (unsigned i = 0; i < T; i++) {
+      uint64_t num;
+      outfile_S >> num;
+      nS_old[i] = num;
+    }
+
+    outfile_S.close();
+  }
+
+  std::ofstream file_out_S(filename_S);
+
+  for (unsigned i = 0; i < T; i++) {
+    file_out_S <<std::fixed<< nS_old[i] + nS[i] << " ";
+  }
+
+  return 0;
+}
+
+
diff --git a/pcg-cpp b/pcg-cpp
new file mode 160000
index 0000000..5b5cac8
--- /dev/null
+++ b/pcg-cpp
@@ -0,0 +1 @@
+Subproject commit 5b5cac8d61339e810c5dbb4692d868a1d7ca1b2d
diff --git a/randutils b/randutils
new file mode 160000
index 0000000..8486a61
--- /dev/null
+++ b/randutils
@@ -0,0 +1 @@
+Subproject commit 8486a610a954a8248c12485fb4cfc390a5f5f854
-- 
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