use only TGraphs

Change to write only TGraphs instead of TMultiGraphs and TCanvases to enable superimposing plots, e.g. as in: https://lblhcbpr.cern.ch/#/app/rootfileviewer?apps=5&withNightly=false&checkSpecific=false&nightlyVersionNumber=10&jobs=61872&jobs=61883 FYI @dovombru @sstahl

handlers/PrCheckerEfficiencyHandler.py

@@ -110,21 +110,22 @@ class PrCheckerEfficiencyHandler(BaseHandler):
                         g_efficiency_electrons.SetLineColor(kAzure-3)
 
                     # draw them both
-                    mg = TMultiGraph()
-                    mg.Add(g_efficiency_notElectrons)
-                    if categories[tracker][cut]["plotElectrons"] :
-                        mg.Add(g_efficiency_electrons)
-
-                    mg.Draw("ap")
                     xtitle = efficiencyHistoDict[histo]["xTitle"]
-                    mg.GetXaxis().SetTitle(xtitle)
-                    mg.GetYaxis().SetTitle("efficiency")
-                    mg.GetYaxis().SetRangeUser(0,1)
+                    g_efficiency_notElectrons.GetXaxis().SetTitle(xtitle)
+                    g_efficiency_notElectrons.GetYaxis().SetTitle("efficiency")
+                    g_efficiency_notElectrons.GetYaxis().SetRangeUser(0,1)
+                    g_efficiency_notElectrons.SetName("efficiency vs. " + histo + " notElectrons")
+                    g_efficiency_notElectrons.Write()
+                    if categories[tracker][cut]["plotElectrons"] :
+                        g_efficiency_electrons.GetXaxis().SetTitle(xtitle)
+                        g_efficiency_electrons.GetYaxis().SetTitle("efficiency")
+                        g_efficiency_electrons.GetYaxis().SetRangeUser(0,1)
+                        g_efficiency_electrons.SetName("efficiency vs. " + histo + " electrons")
+                        g_efficiency_electrons.Write()
 
                     if categories[tracker][cut]["plotElectrons"] :
                         canvas.PlaceLegend()
-                    
-                    canvas.Write()
+
 
             # calculate ghost rate
             histoBaseName = "Track/PrChecker2Fast/" + tracker + "/"
@@ -147,9 +148,9 @@ class PrCheckerEfficiencyHandler(BaseHandler):
                 xtitle = ghostHistoDict[histo]["xTitle"]
                 g_efficiency.GetXaxis().SetTitle(xtitle)
                 g_efficiency.GetYaxis().SetTitle("ghost rate")
-                g_efficiency.Draw("ap")
 
-                canvas.Write()
+                g_efficiency.SetName(title)
+                g_efficiency.Write()
 
         outputfile.Write()
         outputfile.Close()