use 2.38^2/dim as default for scale

src/camel/MCMC/exec/mainMCMC.cc

@@ -50,7 +50,7 @@ int main(int argc, char *argv[])
   }
   string ar_file=string("ar_vs_length_")+fileName;
   string scale_file=string("scale_")+fileName;
-  string cor_file=string("prop_cov_")+fileName;
+  string cor_file=string("last_step_")+fileName;
 
   cout << "output files:" <<endl;
   cout << ar_file << " " << scale_file << " " << cor_file << " " << endl;
@@ -63,7 +63,7 @@ int main(int argc, char *argv[])
   const string proposal_cov=parser.params.find<string>("proposal_cov","");
   const int t0=parser.params.find<int>("t0",2000);
   const int ts=parser.params.find<int>("ts",10000);
-  double scale=parser.params.find<double>("scale",0.001);
+  double scale=parser.params.find<double>("scale",-1);
   const bool do_move=parser.params.find<bool>("do_move",false);
   bool verbose=parser.params.find<bool>("verbose",false);
 
@@ -83,6 +83,11 @@ int main(int argc, char *argv[])
 
   cout <<"dim=" <<dim <<endl;
 
+  //SP 25/06/19: compute scale if undefined depending on dim
+  if (scale<0) {
+      scale=2.38*2.38/dim;
+      cout << "refining scale to " << scale << endl;
+  }
   //--------defining seeds-----------------------------------------------
   unsigned int seed(0);
   if (parser.params.param_present("seed")){