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
This archive was generated by hypermail 2b29 : Sun Jan 02 2005 - 05:50:07 MET