Bug i TGraph->Eval in version 5.24/5.26?

Dear Rooters,

I’ve stumpled upon something that I don’t understand when using TGraph->Eval. Below there is a small root macro which creates a TGraph object directly from a text file (attached) with data. I then use the Eval method to evalute the TGraph at x coordinates which are given in the text file (i.e. root should not do any interpolation). However, the results are wrong

root [0]
Processing MuenSi.C…
TCanvas::MakeDefCanvas: created default TCanvas with name c1
Eval at 1E-3: 866.679
Eval at 1E-2: 47.8911
Eval at 1E-1: 0.0580743

when compared with the same values in the text file. I’ve tested the exact same code using root 5.18 and this works! What happened, or what have I done wrong?

[code]void MuenSi(){

TGraph *g_test = new TGraph(“MuenSi.txt”);

cout<<"Eval at 1E-3: "<<g_test->Eval(1E-3)<<endl;
cout<<"Eval at 1E-2: "<<g_test->Eval(1E-2)<<endl;
cout<<"Eval at 1E-1: "<<g_test->Eval(1E-1)<<endl;

MuenSi.txt (872 Bytes)

there is a bug in TGraph::Eval in 5.26. It has already been fixed in the trunk or in the patch version 5.26.00a:

Best Regards