Hi John,
Ok, since your are using TVirtualFitter, gMinuit
is probably not defined . Have a look at
test/minexam.cxx. Here an object minuit
is defined :
TVirtualFitter *minuit = TVirtualFitter::Fitter(0, 5);
Now you can do just
TFile f("bla.root","RECREATE");
minuit->Write("myfit");
--- "Dr. John Krane" <jkrane@netzero.com> wrote:
> Hi Eddy,
>
> Thanks for the response. I see that the Ifit.C
> routine you mention uses
> a TMinuit object, which I thought was discouraged.
> I am using the
> TVirtualFitter class, which gives me some of that
> lovely "indirection"
> that the kids are all talking about. I wonder if
> this is why my
> gMinuit->Write() command pukes but you think it
> workes in Ifit.C.
>
> Unfortuanately, if it is the case, then I need to
> find out the secret
> name ROOT uses internally for a TVirtualFitter.
> gVirtualFitter maybe.
> I do want to be able to read this back in and use my
> existing code. Or
> come up with something else.
>
> - J
>
> Edmond Offermann wrote:
>
> >Hi John,
> >
> >without more specifics it is hard to tell what
> >goes wrong .
> >If you insert your 2 lines in tutorials/Ifit.C
> >you can check that in principle it does what it is
> >supposed to do
> >
> >Eddy
> >
> >--- "Dr. John Krane" <jkrane@netzero.com> wrote:
> >
> >
> >>Hi,
> >>
> >>Some time ago, I asked how to save intermediate
> >>steps during weeks-long
> >>Minuit fits. The suggested code was simply to do
> >>something like:
> >>
> >> TFile
>
>>f("temp_minuit_intermediate_state.root","RECREATE");
> >> gMinuit->Write();
> >>
> >>
> >>I have a class called "func_fit" that has a
> >>minimization method.
> >>(Because TMinuit wants a bare function, I wrote a
> >>wrapper for the member
> >>function called "dummy_func", visible in the stack
> >>trace below.) My
> >>class increments a counter every time the
> >>minimization method is called;
> >>when I get zero for fmod(counter,10000), I try to
> >>write the TMinuit
> >>object as above. Unfortunately, I get the
> following
> >>stack trace.
> >>
> >>I'm confused as to the source of the problem,
> which
> >>occurs deep in the
> >>Streamer methods. I'm hoping somebody knows what
> >>I'm doing wrong. If
> >>anyone has any advice or proposals for tests, I'll
> >>be very grateful.
> >>
> >> - John
> >>
> >>Program received signal SIGSEGV, Segmentation
> fault.
> >>[Switching to Thread 1091201184 (LWP 24100)]
> >>0x4025d8a2 in ROOT::TObject_IsA(void const*) ()
> from
> >>
> >>/bin/root/lib/libCore.so
> >>(gdb) where
> >>#0 0x4025d8a2 in ROOT::TObject_IsA(void const*)
> ()
> >>from
> >>/bin/root/lib/libCore.so
> >>#1 0x401619b4 in TClass::GetActualClass(void
> >>const*) const () from
> >>/bin/root/lib/libCore.so
> >>#2 0x400ec4ff in TBuffer::WriteObjectAny(void
> >>const*, TClass*) () from
> >>/bin/root/lib/libCore.so
> >>#3 0x4024f7cf in operator<<(TBuffer&, TObject
> >>const*) () from
> >>/bin/root/lib/libCore.so
> >>#4 0x40e9d933 in TMinuit::Streamer(TBuffer&) ()
> >>from
> >>/bin/root/lib/libMinuit.so
> >>#5 0x40101246 in TKey::TKey(TObject*, char
> const*,
> >>int) () from
> >>/bin/root/lib/libCore.so
> >>#6 0x4010e293 in TObject::Write(char const*, int,
> >>int) () from
> >>/bin/root/lib/libCore.so
> >>#7 0x0805297c in func_fit::minimize(int&,
> double*,
> >>double&, double*,
> >>int) (this=0x8059a20, npar=@0xbfffd4f4,
> >>grad=0xd6f56d0, mychi2=@0xbfffd620,
> >> params=0xd6ec0b0, iflag=4) at func_fit.cpp:395
> >>#8 0x080547d5 in dummy_func(int&, double*,
> double&,
> >>double*, int)
> >>(npar=@0xbfffd4f4, grad=0xd6f56d0,
> >>mychi2=@0xbfffd620, params=0xd6ec0b0,
> >>iflag=4)
> >> at fit_idx.cpp:46
> >>#9 0x40e8458d in TMinuit::Eval(int, double*,
> >>double&, double*, int) ()
> >>from /bin/root/lib/libMinuit.so
> >>#10 0x40e8d827 in TMinuit::mnhess() () from
> >>/bin/root/lib/libMinuit.so
> >>#11 0x40e914b7 in TMinuit::mnmigr() () from
> >>/bin/root/lib/libMinuit.so
> >>#12 0x40e8a21a in TMinuit::mnexcm(char const*,
> >>double*, int, int&) ()
> >>from /bin/root/lib/libMinuit.so
> >>#13 0x40e8020f in TFitter::ExecuteCommand(char
> >>const*, double*, int) ()
> >>from /bin/root/lib/libMinuit.so
> >>#14 0x08055296 in main (argc=2, argv=0xbfffe874)
> at
> >>fit_idx.cpp:140
> >>#15 0x420156a4 in __libc_start_main () from
> >>/lib/tls/libc.so.6
> >>
> >>
> >>
> >>
> >
> >
> >
> >
>
> --
>
> Dr. John Krane
> jkrane@netzero.com
>
>
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