# Re: How to draw circle

From: Manoj Kumar Jha <Manoj.Jha_at_cern.ch>
Date: Tue, 18 Jan 2005 18:36:00 +0530

Hi Rene,
I have one more question. The following script is valid when the coordinates of the canvas are positive. For example

```xmin = 0.;
ymin = 0.;
xmax = 2.;
ymax = xmax*h/w;

```

It would be nice if I can plot the circle for the following case also

```xmin = -150.;
ymin = -150.;
xmax = 150.;

```

TEllipse e1(0.,0.,100.,100.);
e1.Draw();

In this case, value of ymax will be changed. I have taken ymax = xmax*(h-xmin)/(w+ymin)

Thanks and with regards,
manoj

On Tue, 2005-01-11 at 21:55, Rene Brun wrote:
> see your example modified below
>
> Rene Brun
>
>
> {
> gROOT->Reset();
> c1 = new TCanvas("c1");
> //compute the pad range to get a fix aspect ratio
> Double_t xmin = 0;
> Double_t xmax = 2;
> Double_t ymin = 0;
> Double_t ymax = xmax*h/w;
> c1->SetFixedAspectRatio();
> c1->Range(xmin,ymin,xmax,ymax);
> TPaveLabel pel(0.1,0.8,0.9,0.95,"Examples of Circle");
> pel.SetFillColor(42);
> pel.Draw();
> TEllipse el1(0.5,0.5,.2,.2);
> el1.Draw();
> }
>
> Manoj Kumar Jha wrote:
> >
> > Dear rooters,
> > I am trying to draw a circle using the attached script. But, I am
> > getting an ellipse (the figure is attached). Could you please let me
> > know where I am committing the mistake ?
> >
> > Thanks,
> > manoj
> > --
> > ***************************************************
> > Manoj Kumar Jha
> > Research Scholar
> > Department of Physics & Astrophysics
> > University of Delhi | Delhi - 110 007 | India
> > Phone : 91-11-27667036(O)
> > E-mail: Manoj.Jha_at_cern.ch
> > ***************************************************
> >
> > --------------------------------------------------------------------------------
> > Name: try.C
> > try.C Type: text/x-c++
> > Encoding: 7bit
> >
> > Name: figure.ps
> > figure.ps Type: Postscript Document (application/postscript)
> > Encoding: 7bit

```--
***************************************************
Manoj Kumar Jha
Research Scholar
Department of Physics & Astrophysics
University of Delhi | Delhi - 110 007 | India
Phone : 91-11-27667036(O)
E-mail: Manoj.Jha_at_cern.ch
***************************************************
```
Received on Tue Jan 18 2005 - 13:57:33 MET

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