to Print the Parameters (not in the TLegend, but it is at least shown). My problem now is to rename the Parameters. There are named “p0” and “p1”, i want them named “y-intersect” and “slope”. I tried
TF1 fitfj1("Linear law","[0]+x*[1]",-5,5);
fitfj1.SetLineColor(kRed); fitfj1.SetLineStyle(2);
fitfj1.SetParName(0,"Y-Intersect")
fitfj1.SetParName(1,"Slope")
fj1.Fit(&fitfj1);
while fj1 is the Import of xy, the fit goes through. The SetParName does not change anything.
Please help me.
It would be easier for me to help you if you send a self-contains running example. What you sent gives me:
Processing farad_1.C...
Error in <TGraphErrors::TGraphErrors>: Cannot open file: messdaten/faraday_j_1.txt, TGraphErrors is Zombie
Warning: fitfj1.SetParName(0,"Y-Intersect") Missing ';' farad_1.C:14:
Warning: fitfj1.SetParName(1,"Slope") Missing ';' farad_1.C:15:
Warning in <Fit>: Fit data is empty
Y-intersect: 0
Y-intersect error: 0
Slope 0
Slope error 0
Error in <TGraphErrors::TGraphErrors>: Cannot open file: messdaten/faraday_j_2.txt, TGraphErrors is Zombie
Warning in <Fit>: Fit data is empty
Error in <TGraphErrors::TGraphErrors>: Cannot open file: messdaten/faraday_s_1.txt, TGraphErrors is Zombie
Warning in <Fit>: Fit data is empty
Error in <TGraphErrors::TGraphErrors>: Cannot open file: messdaten/faraday_s_2.txt, TGraphErrors is Zombie
Warning in <Fit>: Fit data is empty
Info in <TCanvas::Print>: pdf file Faradayeffekt.pdf has been created
root [1] .q
imaccouet:Downloads couet$ vi farad_1.C
imaccouet:Downloads couet$ .x
root [0] .x farad_1.C
Error in <TGraphErrors::TGraphErrors>: Cannot open file: messdaten/faraday_j_1.txt, TGraphErrors is Zombie
Warning: fitfj1.SetParName(0,"Y-Intersect") Missing ';' farad_1.C:14:
Warning: fitfj1.SetParName(1,"Slope") Missing ';' farad_1.C:15:
Warning in <Fit>: Fit data is empty
Y-intersect: 0
Y-intersect error: 0
Slope 0
Slope error 0
Error in <TGraphErrors::TGraphErrors>: Cannot open file: messdaten/faraday_j_2.txt, TGraphErrors is Zombie
Warning in <Fit>: Fit data is empty
Error in <TGraphErrors::TGraphErrors>: Cannot open file: messdaten/faraday_s_1.txt, TGraphErrors is Zombie
Warning in <Fit>: Fit data is empty
Error in <TGraphErrors::TGraphErrors>: Cannot open file: messdaten/faraday_s_2.txt, TGraphErrors is Zombie
Warning in <Fit>: Fit data is empty
Info in <TCanvas::Print>: pdf file Faradayeffekt.pdf has been created