Hello,
Are there documented limitations on the types of things that can be done in
event handlers in root? I have a handler that allows interactive selection
of a region of interest of a histogram using the mouse: One performs the
same mouse operations that are used for zoom along the x-axis. It works
fine, until I add the fitting call - it performs the fit but never returns.
(comment out the fit and it works fine) I use hsimple.root in the
tutorials - any TH1F will work
Here is my root session:
root [0] TFile f("hsimple.root")
root [1] hpx->Draw()
<TCanvas::MakeDefCanvas>: created default TCanvas with name c1
root [2] c1->AddExec("ex1",".x event.c")
root [3] ROI limits: -1.280000 1.280000
FCN=21723.2 FROM MIGRAD STATUS=CONVERGED 73 CALLS 74 TOTAL
EDM=7.24727e-008 STRATEGY= 1 ERROR MATRIX
UNCERTAINTY 1.4 per cent
EXT PARAMETER STEP FIRST
NO. NAME VALUE ERROR SIZE DERIVATIVE
1 Constant 7.95014e+002 2.94883e-001 5.95042e-005 3.14561e-004
2 Mean 9.96928e-003 4.72499e-004 -1.30032e-006 1.79069e-001
3 Sigma 1.00597e+000 7.17379e-004 -5.21731e-006 1.88585e+000
CTRL-C hit !!! ROOT is terminated !
[Note: I had to control-C out - no cpu was being used, root simply hung]
and here is my event handler - event.c
{
//
// This allows selection of an ROI:
//
Float_t roiLo,roiHi;
int ix,ixl,ixh;
int event = gPad->GetEvent();
// only care about Button1Down (1) and Button1Up(11) events
if ((event!=1) && (event!=11) ) return;
TObject *select = gPad->GetSelected();
// only care if selected item is x-axis
if (strcmp(select->GetName(),"xaxis")!=0) return;
ix = gPad->GetEventX();
TAxis *h = (TAxis*)select;
if (event==1) // button down
{
// compute lower limit of ROI
roiLo = gPad->AbsPixeltoX(ix);
ixl = h->FindBin(roiLo);
roiLo = h->GetBinLowEdge(ixl);
}
else // button up
{
// disable event
gPad->DeleteExec("ex1");
// compute upper limit of ROI
roiHi = gPad->AbsPixeltoX(ix);
ixh = h->FindBin(roiHi);
roiHi = h->GetBinLowEdge(ixh)+h->GetBinWidth(ixh);
printf(" ROI limits: %f %f\n",roiLo,roiHi);
TH1F *parent = (TH1F *)h->GetParent();
parent->Fit("gaus","w","",roiLo,roiHi);
}
}
I am running version 3.02/06 of root on Win2000. I am using VC++ v6 w/sp5.
Thanks..
Ed Oltman
This archive was generated by hypermail 2b29 : Sat Jan 04 2003 - 23:50:37 MET