TF1 fitting problem

[Dil]

Hello Rooters,

I have done constant fitting for my plots using TF1(fit a range).
It looked as a “box” type instead of a line.
Any help would be greatly appreciated.

 TF1 *fAve = new TF1("fAve","[0]",-0.06,0.10);
                fAve->SetParameter(0,0.34);
                Efficiency->Fit("fAve","","",-0.06,0.10);

     canEfficiency->cd(k); fAve->SetLineColor(2); fAve->Draw("sames");

[Wile_E_Coyote]

fAve->Draw("LSAME");