diff --git a/homework2/src/write_series.cc b/homework2/src/write_series.cc
index 97f18d4..f60a372 100644
--- a/homework2/src/write_series.cc
+++ b/homework2/src/write_series.cc
@@ -1,36 +1,39 @@
 #include write_series.h
   
 WriteSeries::WriteSeries(Series & series, int frequency, int maxiter){
   this->series = series;
   this->frequency = frequency;
   this->maxiter = maxiter;
 }
 
 void WriteSeries::dump(){
-  std::ofstream file("data.txt")
+  std::string separator = " ";
+  std::string file_name = "data" + setSeparator(separator);
+  std::ofstream file(file_name)
+  file<<i<<separation<<value<<separation<<convergence<<endl;
   for(int i=frequency; i<maxiter; i += frequency){
     double value = series.compute(frequency);
-    file<<"i == "<<i<<" , series == "<<value;
+    file<<i<<separation<<value;
     double analytic_value = series.getAnalyticPrediction();
     if(std::isnan(analytic_value)){
       file<<endl;
     }else{
-      double convergence_percent = (value/analytic_value) * 100.0;
-      file<<" , convergence percent == "<<convergence_percent<<endl;
+      double convergence = (value/analytic_value) * 100.0;  //percent
+      file<<convergence<<endl;
     }
   }
 }
 
 std::string WriteSeries::setSeparator(std::string separator){
   string file_extention;
   if(separator == ","){
     file_extention = ".csv";
   }else if(separator == " " || separator == "\t"){
     file_extention = ".txt";
   }else if(separator == "|"){
     file_extention = ".psv";
   }else{
     cerr<<"Not known file separator !!!";
   }
   return file_extension;
 }