Dear Rooters, I've tried to plot two variables using the features of TBrowser's StartViewer. I dragged the a and b variables (leaves in my data set) onto the x and y places and then I pressed the graph button to issue a plot on a canvas. The result is in the picture /afs/cern.ch/user/c/chiarusi/public/aVSb_browser.ps The variables a and b are respectively the major and minor semiaxis of some ellipses, so b MUST be <= a. Well I startled to the plot since I saw many point getting below the y=x line (i.e. b>a!!!!!). I tried to us<e the scan feature to see which of those were such events with b>a. Root told me that NONE of them was "b>a compliant"! So I wrote a small script verifying inipendently from Root, and I got the same result: none of the events was with b>a! Then I plotted the same events using the TGraph, and I got the plot /afs/cern.ch/user/c/chiarusi/public/aVSb_graph.ps where is perfectly clear that the geometric condition b<=a is completely respected! So, my question is: Is it possible that the StartViewer way of plotting is made via histogramming and not via "TGraph-ing" ? What do you think about swapping this features ? So Scan's results could be confirmed directly by StartViewer's plots. Thanks! Tommaso P.S. I'm using old 3.0 version of root. Do the GetHistogram() or GetXaxis() functions work with a TGraph (let's say in case if I would like to zoom throug the axis ranges )? Thank you very much again. Tommaso
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