Re: reducing TMinuit printout

Good! I've been bitten by this "new" thing a couple of times so I just thought I'd mention it. Unfortunately, I don't know the answer to your real question.

-Art S.

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On Fri, 1 May 2009, Tom Roberts wrote:

> OK. In my case, evaluating FCN is much more expensive than the new, and is
> done ~100 times more often. So the new is negligible.
>
>
> Tom Roberts
>
>
>
> Arthur E. Snyder wrote:
>> You might want to make only one TMinuit for another reason, if you're using
>> it a lot as would be indicated by your desire to reduce print. That is
>> "new" is rather expensive in C++ and if your fit is pretty simple and
>> you're just doing the fit many times, the "new" many times might be a big
>> contributor to the CPU used. Using a single instance should not be a
>> problem as long as you reset parameters to appropriate initial values
>> before each fit.
>>
>> -Art S.
>>
>> A.E. Snyder, Group EC \!c*p?/
>> SLAC Mail Stop #95 ((. .))
>> Box 4349 |
>> Stanford, Ca, USA, 94309 '\|/`
>> e-mail:snyder_at_slac.stanford.edu o
>> phone:650-926-2701 _
>> http://www.slac.stanford.edu/~snyder BaBar
>> FAX:650-926-2657 Collaboration
>>
>>
>>
>> On Fri, 1 May 2009, Tom Roberts wrote:
>>
>>> I am using TMinuit for a special fitting task, and am creating a TMinuit
>>> object and calling Migrad() thousands of times. This completely overwhelms
>>> the output, because it prints a page per call. This is a large C++
>>> simulation program linked with the Root libraries.
>>>
>>> How can I avoid ALL printout from TMinuit() and Migrad() ?
>>>
>>> I'm now doing this:
>>> TMinuit *tm = new Tminuit();
>>> tm->SetPrintLevel(0);
>>> tm->Command("SET PRINTOUT -1");
>>> ... use tm
>>>
>>> But I still get 3 lines per instance:
>>> **********
>>> ** 1 **SET PRINT 0
>>> **********
>>>
>>> How can I avoid that? It seems to be using the global function Printf(),
>>> which I could not find in the reference manual and there's no source file
>>> Printf.cxx. I am willing to omit even warnings and error messages, so how
>>> can I turn Printf() off?
>>>
>>> I tried:
>>> stderr = stdout = fopen("/dev/null","w");
>>> but that did not stop the output (!).
>>>
>>>
>>> Perhaps I could just create a single TMinuit object and re-use it, thus
>>> reducing this to 3 rather strange lines of output. But that requires
>>> changing a lot of code, and I'd rather not do it (how much state from the
>>> previous fit does TMinuit keep? -- I don't know, and would rather not make
>>> my program depend on the answer).
>>>
>>>
>>> Tom Roberts
>>>
>>>
>
>
Received on Fri May 01 2009 - 21:52:07 CEST