#14 plotNLL for RooSim pdfs

[Alessio Sarti]

Hi,
I'd like to know what is the correct syntax for
producing an NLL plot for Sim pdfs.

Usually I use
RooPlot *p;
RooDataSet& pl_data;
with p obtained from
p = myVar->frame(tmpMin,tmpMax,50);
pdf.plotNLLOn(&*p,&pl_data,"L",1.0,kTRUE);

If the pdf is a roosim one and I blindly use the same
syntax I get a crash.

But I think that this has to do with the fact the
pl_data needs to be projected [am I right]?

I've tried with
pdf.plotNLLOn(&*p,ProjWData(*omegaB0Cat,pl_data),"L",1.0,kTRUE);

but this is not working [does not compile].
Any hint? Or help?
Alessio