How to remove line on the fitting plane

ROOT
1

ROOT Version: 6.22/08
Platform: Ubuntu20.04

Dear experts,
I try to remove the red line on the fitting plane as shown on the plot below, but I have no idea about it,
could you please help me, thanks very much.
The code is also attached.

rr.C (628 Bytes)
fitting

Best regards,
Jiechen

2

Dear Jiechen,

I add in the loop @couet , who will know how to address this.

Best,
D

3

Thank you, Danilo.

@couet, hi, Couet. I don’t know how to remove the red line shown on plot, could you please help me check it? Thank you very much.

Best regards,
Jiechen

4

I am looking at it. I do not know yet.

5

This is the contour level of the fit. I do not really know wht it shows up n that case only. But you can remove it with:

   f1->SetLineColorAlpha(2,0.);
6

Hi, Couet,
Thank you for helping, I try to use your way, but it does work whatever adding in any line.
Is something wrong in the attached code?
rr.C (745 Bytes)

Best regards,
Jiechen

7

Ah yes sorry, transparency does not work on all platforms. Better do:

double fitf(Double_t *x,Double_t *par){
   double fitval=(par[0]*x[0]+par[1]*x[1]+par[2]);
   return fitval;
}

void rr()
{
   const int bin = 40;
   auto c = new TCanvas("c","c",800,600);
   auto h = new TH3F("h","h",bin,0,50,bin,0,50,bin,0,50);
   TRandom ran;
   double nn = 22;
   for (int i=0; i<5000; i++) {
      h->Fill(ran.Poisson(nn),ran.Poisson(nn),ran.Poisson(10)+10);
   }
   auto f1 = new TF2("f1",fitf,0,50,0,50,3);
   f1->SetLineWidth(0.);
   f1->SetParameters(1,1,10);
   f1->SetMinimum(0);
   f1->SetMaximum(50);

   h->Fit(f1);
   f1->Draw("surf2");
   h->Draw("same BOX2 Z");
}
8

Hi, Couet,
It works based on your way, thank you very much.

Best regards,
Jiechen