diff --git a/cpp/switchchain_ecm_initialtris.cpp b/cpp/switchchain_ecm_initialtris.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..df1baff263237534835e3d8a02229a226e660c16
--- /dev/null
+++ b/cpp/switchchain_ecm_initialtris.cpp
@@ -0,0 +1,133 @@
+#include "switchchain.hpp"
+#include "exports.hpp"
+#include "graph.hpp"
+#include "graph_ecm.hpp"
+#include "graph_powerlaw.hpp"
+#include <algorithm>
+#include <fstream>
+#include <iostream>
+#include <numeric>
+#include <random>
+#include <vector>
+
+int main(int argc, char *argv[]) {
+    // Simulation parameters
+    const int numVerticesMin = 1000;
+    const int numVerticesMax = 10000;
+    const int numVerticesStep = 1000;
+
+    float tauValues[] = {2.05f, 2.1f, 2.2f, 2.3f, 2.4f, 2.5f,
+                         2.6f,  2.7f, 2.8f, 2.9f, 2.95f};
+
+    auto getMixingTime = [](int n, float tau) {
+        return int(50.0f * (50.0f - 5.0f * (tau - 2.0f)) * n);
+    };
+    auto getMeasurements = [](int n, float tau) {
+        (void)n;
+        (void)tau;
+        return 5000;
+    };
+    auto getMeasureSkip = [](int n, float tau) {
+        (void)tau;
+        return 30 * n; // Take a sample every ... steps
+    };
+
+    // Output file
+    std::ofstream outfile;
+    if (argc >= 2)
+        outfile.open(argv[1]);
+    else
+        outfile.open("graphdata_ecm_initialtris.m");
+    if (!outfile.is_open()) {
+        std::cout << "ERROR: Could not open output file.\n";
+        return 1;
+    }
+
+    // Output Mathematica-style comment to indicate file contents
+    outfile << "(*\n";
+    outfile << "n from " << numVerticesMin << " to " << numVerticesMax
+            << " step " << numVerticesStep << std::endl;
+    outfile << "tauValues: " << tauValues << std::endl;
+    outfile << "Canonical degree sequence.\n";
+    outfile << "mixingTime: 50 * (50 - 5 (tau - 2)) n\n";
+    outfile << "measurements: 5000\n";
+    outfile << "measureSkip: 30 n\n";
+    outfile << "data:\n";
+    outfile << "1: {n,tau}\n";
+    outfile << "2: {uniform tri samples}\n";
+    outfile << "3: {ECM initial tri samples} \n";
+    outfile << "*)" << std::endl;
+
+    // Mathematica does not accept normal scientific notation
+    outfile << std::fixed;
+    outfile << '{' << '\n';
+    bool outputComma = false;
+
+    std::mt19937 rng(std::random_device{}());
+    Graph g;
+    for (int numVertices = numVerticesMin; numVertices <= numVerticesMax;
+         numVertices += numVerticesStep) {
+        for (float tau : tauValues) {
+            int mixingTime = getMixingTime(numVertices, tau);
+            int measurements = getMeasurements(numVertices, tau);
+            int measureSkip = getMeasureSkip(numVertices, tau);
+
+            // For a single n,tau take samples over several instances of
+            // the degree distribution.
+            DegreeSequence ds;
+            generateCanonicalPowerlawGraph(numVertices, tau, g, ds);
+
+            std::cout << "Running (n,tau) = (" << numVertices << ',' << tau
+                      << ")." << std::flush;
+
+            //
+            // ECM triangles
+            //
+            std::vector<int> ECMtris;
+
+            for (int i = 0; i < measurements; ++i) {
+                Graph gtemp;
+                if (erasedConfigurationModel(ds, gtemp, rng)) {
+                    ECMtris.push_back(gtemp.countTriangles());
+                }
+            }
+
+            std::cout << " Finished ECM samples." << std::flush;
+
+            // Uniform triangles
+            std::vector<int> uniformTris;
+
+            SwitchChain chain;
+            if (!chain.initialize(g)) {
+                std::cerr << "Could not initialize Markov chain.\n";
+                return 1;
+            }
+
+            for (int i = 0; i < mixingTime; ++i) {
+                chain.doMove();
+            }
+            chain.g.getTrackedTriangles() = chain.g.countTriangles();
+            for (int i = 0; i < measurements; ++i) {
+                for (int j = 0; j < measureSkip; ++j)
+                    chain.doMove(true);
+                uniformTris.push_back(chain.g.getTrackedTriangles());
+            }
+
+            std::cout << " Finished uniform samples." << std::flush;
+
+            if (outputComma)
+                outfile << ',' << '\n';
+            outputComma = true;
+
+            outfile << '{';
+            outfile << '{' << numVertices << ',' << tau << '}';
+            outfile << ',' << uniformTris;
+            outfile << ',' << ECMtris;
+            outfile << '}' << std::flush;
+
+            std::cout << std::endl;
+        }
+    }
+    outfile << '\n' << '}';
+    return 0;
+}