Hi Daniel, The Probleme in your piece of code is with gROOT->Delete("mycut"). This statement will no nothing if your cut is not drawn on the screen. When a TCutG object is created , it is automatically added to the list of special ROOT objects, that you can retrieve with a statement like: TCutG *mycut = (TCutG*)gROOT->GetListOfSpecials()->FindObject("mycut") In order to delete your cut, you should first get a pointer to it via the avove statement, then do delete mycut; You can also delete a cut via the mouse using the contextmenu item "Delete" when your cut is drawn on the screen. see http://root.cern.ch/root/html/TCutG.html Rene Brun Daniel Barna wrote: > > Hi Rene, > I am using v2.25 on a linux pc. > These are the steps I made: > > TFile file("file.root"); > TTree *t = (TTree *)file.Get("tree"); > t->Draw("x:z"); > > //Now I create a TCutG with the graphics editor, and rename it to "mycut". > > t->Draw("x:z","mycut"); > // it works fine, only points in the selected area appear on the screen > > gROOT->Delete("mycut"); > t->Draw("x:z"); > > // now I create another TCutG with the graphics editor, and rename > // it again to "mycut" > > t->Draw("x:z","mycut"); > > // at this step TTree::Draw seems to use the previous cut, the produced > // plot is the same as before > > Daniel > > > Hi Daniel, > > I do not understand this problem. Which version are you using ? > > What do you mean by "deleting the cut from the current directory" ? Could > > you provide a snapshot of your code with the calls to create the cut, > > delete it ? Note that I am currently on holidays with sporadic access to > > the internet. > > > > Rene Brun > > > > On Thu, 27 Jul 2000, Daniel Barna wrote: > > > > > Hi Rooters, > > > I created a TCutG object by setting it's points in a > > > fuction. It worked fine when I used it in a selection of TTree::Draw. > > > Later I deleted this TCutG object from the root directory, and created a > > > new TCutG object with the same name, but TTree::Draw > > > didn't recognize the change: it used still the old cut. > > > What is the right way to avoid such a case? > > > Thanks > > > Daniel > > > > > >
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