Re: Defining TF2 functions and doing fits in for loop

I should have been more careful but I could not see it. Thank you very much for pointing out.
Best regards, - Nevzat

> Hi,
>
> All your fit functions have the same name, replacing existing ones. If you use
> is instead of isize in the call to sprintf it should work.
>
> Cheers, Axel
>
> nguler_at_jlab.org wrote:
>
>>Hello All,
>>
>>I am using root 5.26-00-64bit. I have a TH2F object:
>>
>> TH2F *histsim = new TH2F(histsimName,histsimName,256,0,256,256,0,256);
>>
>>Then I define fit functions:
>>
>> TF2 *fitsim1_5 =
>> new
>>TF2("fitsim1_5",Gaus2D,jVec[0]-range,jVec[0]+range,iVec[0]-range,iVec[0]+range,5);
>> fitsim1_5->SetParameters(pVec[0]/100,jVec[0],1.,iVec[0],1.);
>>
>> TF2 *fitsim2_5 =
>> new
>>TF2("fitsim2_5",Gaus2D,jVec[1]-range,jVec[1]+range,iVec[1]-range,iVec[1]+range,5);
>> fitsim2_5->SetParameters(pVec[1]/100,jVec[1],1.,iVec[1],1.);
>>
>>and fit the histogram:
>>
>> histsim->Fit("fitsim1_5","RN");
>> histsim->Fit("fitsim2_5","RN");
>>
>>And it works. However, I would like to create the fit functions in a
>>loop and
>>make the fitting in the same loop for several different regions, such
>>as:
>>
>>const int isize = pVec.size(); //// isize = 2 since there are two peaks
>>to
>>fit here.
>> TF2 *fitarr[isize];
>> for (int is=0; is<isize; is++)
>> {
>> char afitn[20];
>> int range = 10;
>> sprintf(afitn, "fitsim3_%d", isize);
>> double xmin = double(jVec[is] -range);
>> double xmax = double(jVec[is] +range);
>> double ymin = double(iVec[is] -range);
>> double ymax = double(iVec[is] +range);
>> double xctr = double(jVec[is]);
>> double yctr = double(iVec[is]);
>> double peak = double(pVec[is]/100);
>>
>> fitarr[is] = new TF2(afitn,Gaus2D,xmin,xmax,ymin,ymax,5);
>> fitarr[is]->SetParameters(peak,xctr,1.,yctr,1.);
>>
>> fitarr[is]->SetLineColor(kBlack);
>> histsim->Fit(afitn,"RN+");
>> fitarr[is]->SetRange(0,0, 256,256);
>> fitarr[is]->SetMaximum(histsim->GetMaximum());
>> fitarr[is]->Draw("cont1, same");
>> gPad->Modified();
>> gPad->Update();
>> }
>>
>>When I do this, it only plots the last fit in the loop. The first fit
>>is lost
>>somewhere and not plotted. If I do the loop only for one fit function
>>(by
>>changing isize to 1), it plots the first fit. When isize =2, it only
>>plots the
>>second fit. I don't see any difference between the first method (which
>>works)
>>and the second method (that fails). Unfortunately I am not able to send
>>a
>>working code since the input files are rather big. But the main idea is
>>to do
>>multiple fits on the same histogram (on different ranges of it) by
>>using a for
>>loop. I appreciate your comments if I am doing something wrong in the
>>for
>>loop.
>>Thanks,
>>
>>- Nevzat Guler
>>(757) 553-8318
>
>

• Nevzat Guler (757) 553-8318