Hi Tony, Did you start from the CVS source with the tag 3-03-02 or from the CVS head? I implemented this change only last night ! This morning, I have added additional protections in TGraph::ExecuteEvent in case you zoom with very large factors. Rene Brun Colley, Tony wrote: > > By the way, I just did a CVS update, remade & reinstalled ROOT, and now am > running ROOT 3.03/02... > > and the problem described below still exists. > > -----Original Message----- > From: Colley, Tony > Sent: Tuesday, February 26, 2002 15:37 > To: 'ROOT Talk' > Subject: zoomed in TGraph bug > > The following demonstrates a "minor" bug in TGraph: > > { > Int_t i; > Float_t x[1000]; > Float_t y[1000]; > > for (i=0; i<1000; i++) > { > x[i] = 0.001*i; > y[i] = 6.2831853*x[i]; > y[i] = sin(12*y[i]) + sin(17*y[i]) + sin(56*y[i]) + sin(74*y[i]); > } > > TGraph *graph = new TGraph( 1000, x, y ); > graph->Draw("AL"); > > printf( > "\n\n===============================================================\n" ); > printf( "Right click on X axis and select SetRangeUser.\n" ); > printf( "Enter the range 0.387 to 0.389 and click OK.\n" ); > printf( "Move the cursor over one of the 3 points (at .387, .388, .389).\n" > ); > printf( "Press down the left mouse button.\n" ); > printf( "When I do it, there are 6 extra boxes drawn\n" ); > printf( " (in addition to the three that should be drawn)\n" ); > printf( "===============================================================\n" > ); > } > > (I've attached the same thing as tgdemo.C, in case that's easier to use than > just cutting/pasting from this email) > > The y function was chosen arbitrarily. The bug appears for many other > functions I tried. > > The bug is even more insidious when you significantly increase the number of > data points graphed. When you zoom in close enough to begin seeing > individual points, in addition to having many extra boxes, some boxes are > apparently drawn too close to the edges because there is a wraparound effect > (giving rectangles spanning the graph rather than little boxes around the > points). > > I also noticed in the example I provided, if you don't zoom in quite so far, > there are extra boxes drawn extending out of the left and right sides of the > graph. These boxes seem to correspond to data points outside the graph > clipping area but within the canvas clipping area. I'm not sure if I would > classify this behaviour as a bug or a feature... it could be useful and may > be intentional (i.e. a feature). > > Tony Colley > ITT Industries A/CD > Fort Wayne, IN USA > > Using ROOT 3.03/00, last updated from CVS on 18 Feb 2002, on RedHat Linux > 7.2 > > ************************************ > If this email is not intended for you, or you are not responsible for the > delivery of this message to the addressee, please note that this message may > contain ITT Privileged/Proprietary Information. In such a case, you may not > copy or deliver this message to anyone. You should destroy this message and > kindly notify the sender by reply email. Information contained in this > message that does not relate to the business of ITT is neither endorsed by > nor attributable to ITT. > ************************************
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