void Scatter(){

 gStyle->SetStripDecimals(0);

 const char *inputFile = "data.txt";
 const char *outFile = "out.pdf";

  TCanvas *c1 = new TCanvas(outFile,"A Simple Graph Example",780,550);
  c1->SetTickx();
  c1->SetTicky();
  TGraph2D *g_temp = new TGraph2D(inputFile,"%*s %lg %*s %lg %lg");

  g_temp->Draw("x:y:z","colz"); 

 c1->Print(outFile);
}