Alphanumeric labels

I’m trying to plot some data points with alphanumeric expressions on the x axis. I followed example hlabels2.C but it just doesn’t work:

const int n = 3;
double par1[n] = {x1,x3,x4}; // x1,x3,x4 are parameter that were evaluated before in the macro
char *date[n] = {“April”,“Mid July”,“End of Sept”};
TH2F *h = new TH2F(“h”,“variation of center position”,3,0,3,10,0,10);
h->SetBit(TH1::kCanRebin);
h->SetStats(0);

for(int i=1;i<4;i++) {
h->Fill(date[i],par1[i]);
}

h->LabelsDeflate();
h->LabelsOption(“v”);
h->Draw(“text”);

gives: Warning in TH2F::LabelsOption: Cannot sort. No labels

help, please!

cheers,
Kati

See the help of LabelsOption
root.cern.ch/root/html/TH1.html#TH1:LabelsOption
It has 2 parameters,
the 2nd has the value “X” by default.
You need “Y”