Errors bars

Hi Rene,

I know this............or maybe I'll tell you what I am trying to do. I need to compare data with HIJING, where data has to be drawn with markers(along with errors) and HIJING with lines. So if I use "ALP", it draws
everything with line. I need in one canvas with line and markers represented.
I tried using two multigraph but somehow I couldn't succeed.

Thanks for all your help.

Monika

Rene Brun wrote:

> Monika,
>
> If you create a TGraphErrors you don't need to create individual
> TMarkers. Simply do:
> Float_t x1[] = {Some values..........}
> Float_t y1[] = {Some values..........};
> Float_t ex[] = {0,0,0,0,0,0,0};
> Float_t ey[] = {0,0,0,0,0,0,0};
> gr1 = new TGraphErrors(n,x1,y1,ex,ey);
> gr1->SetMarkerColor(kBlue);
> gr1->SetMarkerSize(1.2);
> gr1->Draw("ap");
>
> Rene Brun
>
>
>
> Monika Sharma wrote:
>
>>
>> Hi Rene,
>>
>> I tried it this way :
>>
>> =======================================
>> Float_t x1[] = {Some values..........}
>> Float_t y1[] = {Some values..........};
>> Float_t ex[] = {0,0,0,0,0,0,0};
>> Float_t ey[] = {0,0,0,0,0,0,0};
>> gr1 = new TGraphErrors(n,x1,y1,ex,ey);
>> Double_t *nx = gr1->GetX();
>> Double_t *ny = gr1->GetY();
>> Double_t *ney = gr1->GetEY();
>> Double_t *nex = gr1->GetEX();
>>
>> for(Int_t i=0; i<8; i++)
>> {
>> TMarker *m = new TMarker(nx[i],ny[i],nex[i],ney[i],22);
>> m->SetMarkerColor(kBlue);
>> m->SetMarkerSize(1.2);
>> m->Draw();
>> }
>> ===========================================
>>
>> But looks like I can only pass (gr1->GetX(), gr1->GetY(), MarkerStyle)
>> and not the errors. Is there any way that I draw errors on these
>> markers?
>> Also, I didn't fine any function in TMarker class which can return me
>> errors in gr1.
>>
>> Thanks
>> Monika
>>
>> Rene Brun wrote:
>>
>>> Monika Sharma wrote:
>>>
>>>>
>>>> Hi Rooters,
>>>>
>>>> I have been using the demo example given in Chapter 4 (Graphs),
>>>> page 53,
>>>> in User's guide. This program draws markers with different colours
>>>> taking
>>>> input from graph, i.e.,
>>>>
>>>> Double_t *nx = gr3->GetX();
>>>> Double_t *ny = gr3->GetY();
>>>>
>>>> I wanted to ask is there any way with which it can take errors
>>>> too........
>>>> Something like :
>>>>
>>>> Double_t *nex = gr4->GetEX();
>>>> where gr4 is TGraphErrors and EX is the error on x
>>>> Is it possible?
>>>
>>>
>>>
>>> YES. In the example replace TGraph by TGraphErrors and define your
>>> errors in x and/or y
>>>
>>> Rene Brun
>>>
>>>>
>>>> Thanks
>>>> Monika
>>>
>>>
>>>
Received on Mon Jan 29 2007 - 08:42:11 CET