diff --git a/src/one-body-sample.cc b/src/one-body-sample.cc
index d51ffa4b98571a26ee3b856b9e26b5f910b2a67f..fbe1792b644661d075dc4e2b469fcbcdf6f8bdb8 100644
--- a/src/one-body-sample.cc
+++ b/src/one-body-sample.cc
@@ -208,6 +208,7 @@ int main(int argc, char *argv[]) {
              ignoreNodes);
 
     std::fstream octave_writer("data", std::fstream::out);
+    std::fstream coefficient_writer("coefficient", std::fstream::out);
     timer.reset();
     auto const timesteps = parset.get<size_t>("timesteps");
     octave_writer << "# name: A" << std::endl << "# type: matrix" << std::endl
@@ -298,8 +299,9 @@ int main(int argc, char *argv[]) {
             auto const eta = parset.get<double>("boundary.friction.eta");
             auto const mu = parset.get<double>("boundary.friction.mu");
 
-            std::cout << mu + a *std::log(V * eta) +
-                             b * (state - std::log(eta * L)) << std::endl;
+            coefficient_writer << mu + a *std::log(V * eta) +
+                                      b * (state - std::log(eta * L))
+                               << std::endl;
 
             break;
           }
@@ -328,6 +330,7 @@ int main(int argc, char *argv[]) {
               << timer.elapsed() << "s" << std::endl;
 
     octave_writer.close();
+    coefficient_writer.close();
 
     if (parset.get<bool>("printFrictionalBoundary")) {
       // Print displacement on frictional boundary