diff --git a/demos/mcapi_povcdl_estimation.cpp b/demos/mcapi_povcdl_estimation.cpp
index 0faa3a3514d4bfe0ee1e0c70441ddc11da17e0ae..4543cd6c6a15da77b95dc0adcd760243196c6543 100644
--- a/demos/mcapi_povcdl_estimation.cpp
+++ b/demos/mcapi_povcdl_estimation.cpp
@@ -666,25 +666,25 @@ int main (int argc, char **argv) {
         state_est = problem->getState(t_arr[i]);
         file_est << std::setprecision(std::numeric_limits<long double>::digits10 + 1)
                  << t_arr[i] << ","
-                 << state_est["P"](0) << ","
-                 << state_est["P"](1) << ","
-                 << state_est["P"](2) << "," 
-                 << state_est["O"](0) << "," 
-                 << state_est["O"](1) << "," 
-                 << state_est["O"](2) << "," 
-                 << state_est["O"](3) << "," 
-                 << state_est["V"](0) << "," 
-                 << state_est["V"](1) << "," 
-                 << state_est["V"](2) << "," 
-                 << state_est["C"](0) << ","
-                 << state_est["C"](1) << ","
-                 << state_est["C"](2) << "," 
-                 << state_est["D"](0) << "," 
-                 << state_est["D"](1) << "," 
-                 << state_est["D"](2) << "," 
-                 << state_est["L"](0) << "," 
-                 << state_est["L"](1) << "," 
-                 << state_est["L"](2)
+                 << state_est['P'](0) << ","
+                 << state_est['P'](1) << ","
+                 << state_est['P'](2) << "," 
+                 << state_est['O'](0) << "," 
+                 << state_est['O'](1) << "," 
+                 << state_est['O'](2) << "," 
+                 << state_est['O'](3) << "," 
+                 << state_est['V'](0) << "," 
+                 << state_est['V'](1) << "," 
+                 << state_est['V'](2) << "," 
+                 << state_est['C'](0) << ","
+                 << state_est['C'](1) << ","
+                 << state_est['C'](2) << "," 
+                 << state_est['D'](0) << "," 
+                 << state_est['D'](1) << "," 
+                 << state_est['D'](2) << "," 
+                 << state_est['L'](0) << "," 
+                 << state_est['L'](1) << "," 
+                 << state_est['L'](2)
                  << "\n"; 
         
         file_wre << std::setprecision(std::numeric_limits<long double>::digits10 + 1)
@@ -723,28 +723,28 @@ int main (int argc, char **argv) {
 
             file_kfs << std::setprecision(std::numeric_limits<long double>::digits10 + 1)
                      << kf->getTimeStamp().get() << ","
-                     << kf_state["P"](0) << ","
-                     << kf_state["P"](1) << ","
-                     << kf_state["P"](2) << "," 
-                     << kf_state["O"](0) << "," 
-                     << kf_state["O"](1) << "," 
-                     << kf_state["O"](2) << "," 
-                     << kf_state["O"](3) << "," 
-                     << kf_state["V"](0) << "," 
-                     << kf_state["V"](1) << "," 
-                     << kf_state["V"](2) << "," 
-                     << kf_state["C"](0) << "," 
-                     << kf_state["C"](1) << "," 
-                     << kf_state["C"](2) << "," 
-                     << kf_state["D"](0) << "," 
-                     << kf_state["D"](1) << "," 
-                     << kf_state["D"](2) << "," 
-                     << kf_state["L"](0) << "," 
-                     << kf_state["L"](1) << "," 
-                     << kf_state["L"](2) << ","
-                     << bp_bias_est["I"](0) << ","
-                     << bp_bias_est["I"](1) << ","
-                     << bp_bias_est["I"](2)
+                     << kf_state['P'](0) << ","
+                     << kf_state['P'](1) << ","
+                     << kf_state['P'](2) << "," 
+                     << kf_state['O'](0) << "," 
+                     << kf_state['O'](1) << "," 
+                     << kf_state['O'](2) << "," 
+                     << kf_state['O'](3) << "," 
+                     << kf_state['V'](0) << "," 
+                     << kf_state['V'](1) << "," 
+                     << kf_state['V'](2) << "," 
+                     << kf_state['C'](0) << "," 
+                     << kf_state['C'](1) << "," 
+                     << kf_state['C'](2) << "," 
+                     << kf_state['D'](0) << "," 
+                     << kf_state['D'](1) << "," 
+                     << kf_state['D'](2) << "," 
+                     << kf_state['L'](0) << "," 
+                     << kf_state['L'](1) << "," 
+                     << kf_state['L'](2) << ","
+                     << bp_bias_est['I'](0) << ","
+                     << bp_bias_est['I'](1) << ","
+                     << bp_bias_est['I'](2)
                      << "\n"; 
         }
     }