void test()
{

TCanvas *c = new TCanvas();

TFile *f =new TFile("tpc_data_2008_11_18_09_55_46.root");


cout<<datatree->GetEntries()<<endl;

for (unsigned int i=0; i<10; i++){
	c->Clear();
	c->cd();
	
      	//Fill TProfile2D histogram.
    	datatree->Draw("tAmp:tTime:tChannelId>>tAmpVstTimeVsChId");
    	//set the attributes and draw the plot.
  c->Update();
  c->Modified();
}
return;
}