Fit TH1D with voigt function

ROOT
1

This is what I tried:

[code]fitFcn=r.TF1(“fitFcn”,r.TMath.Voigt,-80,80,3)
fitFcn.SetParameter(0, 1)
fitFcn.SetParameter(1, 1)
fitFcn.SetParameter(2, 1)
fitFcn.SetLineWidth(4)
fitFcn.SetLineColor(r.kMagenta)
rootValX.Fit(“fitFcn”)

rootValX.Draw(“E1”)[/code]

Error message:

TypeError: double TMath::Voigt(double x, double sigma, double lg, int r = 4) =>
    takes at least 3 arguments (2 given)
Traceback (most recent call last):
  File "readBinsRoot.py", line 47, in <module>
    rootValX.Fit("fitFcn")
Exception: TFN python function call failed (C++ exception of type runtime_error)

What am I doing wrong?

2

Try something like:
fitFcn = r.TF1(“fitFcn”, “TMath::Voigt(x - [0], [1], [2], 4)”, -80, 80)
or:
fitFcn = r.TF1(“fitFcn”, “[0] * TMath::Voigt(x, [1], [2], 4)”, -80, 80)