Change TH2F y axis label

[Tanvi_Wamorkar]

Hello,

I want to change the labels of a TH2F’s y axis.
I attempt to do it this way:

c = ROOT.TCanvas()

f_in = ROOT.TFile("training.root","read")
CorrelationMatrixB = f_in.Get("Correlations/CorrelationMatrixB")
y = CorrelationMatrixB.GetYaxis()
y.ChangeLabel(14,-1,-1,-1,-1,-1,"m(h)")
y.SetLabelSize(0.03)

CorrelationMatrixB.Draw("COLZ TEXT")
c.Draw()

But the result remains unchanged. I am, however, able to perform similar operations on the x axis.

Could you please let me know why this doesnt work with the y axis and how to change the labels?

Thank you in advance,
Tanvi

[couet]

I guess your Y label are alphanumeric labels ? ChangeLabel does not work on them.

[Tanvi_Wamorkar]

The Y and X labels are the same, and this worked on the X axis. So maybe thats not the problem?

[couet]

Ah ok. so I am wrong. Can you post the root file ? I will look at it.

[Tanvi_Wamorkar]

CorrelationMatrixB.root (5.5 KB)

I uploaded a root file with just the TH2F. Many thanks for taking a look at it.

[couet]

With the following example I see what you described (ok on X but not on Y). I need to debug.

{
   auto f_in = new TFile("CorrelationMatrixB.root");
   TH2F*  CorrelationMatrixB = (TH2F*)f_in->Get("CorrelationMatrixB");
   TAxis *y = CorrelationMatrixB->GetYaxis();
   y->ChangeLabel(14,-1,-1,-1,-1,-1,"YYY");
   TAxis *x = CorrelationMatrixB->GetXaxis();
   x->ChangeLabel(14,-1,-1,-1,-1,-1,"XXX");

   CorrelationMatrixB->Draw("COLZ TEXT");
}

[Tanvi_Wamorkar]

Okay, thank you.

[dastudillo]

Try with SetBinLabel(14,"m(h")) instead of ChangeLabel.

[Tanvi_Wamorkar]

CorrelationMatrixB.GetYaxis().SetBinLabel(14,“m(h)”)

this works!

[couet]

I made a pull request to fix the ChangeLabel issue. It should work also.

ChangeLabel was not fully implemented on alphanumeric labels.

Thanks to have seen it.

[Tanvi_Wamorkar]

Thank you!

[couet]

This PR is now merged.