HI ,

I am using the following code:

binc[2] = new TH1F(“binc_2”,“3<Enu<4”,20,2,3);

// then fill binc[2]

TF1 *f3 = new TF1(“f3”,“pol3”);

binc[2]->Fit(“f3”);

integral_val[2]=f3->Integral(1.0,2.0);

…

I am a little confused because I see a non zero value returned for the f3 integral between 1.0 and 2.0. But since my historgram is between 2 and 3, i would expect the f3 to be between 2 and 3 and 0 outside this range. Is f3 extrapolating for the region outside the 2 and 3 limits ?