Re: [ROOT] X and Y axis not handled consistently in TGraph.

From: Rene Brun (Rene.Brun@cern.ch)
Date: Mon Sep 09 2002 - 21:21:59 MEST 

Hi Brett,
Do:
void gtest1 (void)
{
    graph = new TGraph();
    int i;
    for (i=0; i<10; ++i) {
        graph->SetPoint(i,i+0.5,i+0.5);
    }
    graph->Draw("A*");
    ax = graph->GetXaxis();
    ay = graph->GetYaxis();
    ax->SetRangeUser(2.0,4.0);
    graph->SetMinimum(2);
    graph->SetMaximum(4);
    c1->Modified();
}

or better

void gtest2 (void)
{
    graph = new TGraph();
    int i;
    for (i=0; i<10; ++i) {
        graph->SetPoint(i,i+0.5,i+0.5);
    }
    TCanvas *c1 = new TCanvas();
    c1->DrawFrame(2,2,4,4);
    graph->Draw("*");
}

Rene Brun

On Mon, 9 Sep 2002, Brett Viren wrote:

> Hi,
> 
> I want to have control over the range of X and Y axis in a TGraph, but
> attempts to change the Y range go ignored.  As an example:
> 
> 
> // graph_test.C
> TCanvas* canvas=0;
> TGraph* graph = 0;
> TAxis *ax=0, *ay=0;
> void graph_test (void)
> {
>     graph = new TGraph();
>     int i;
>     for (i=0; i<10; ++i) {
>         graph->SetPoint(i,i+0.5,i+0.5);
>     }
>     graph->Draw("A*");
>     ax = graph->GetXaxis();
>     ay = graph->GetYaxis();
>     ax->SetRangeUser(2.0,4.0);
>     ay->SetRangeUser(2.0,4.0);
>     c1->Modified();
> }
> // end graph_test.C
> 
> 
> Running this, only the X range is modified.  Is this a bug or a
> feature?
> 
> If the latter, how can I modify the Y range (that is, from code not
> interactively).
> 
> Thanks,
> -Brett.
>

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