Re: reducing TMinuit printout

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.

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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 - 21:34:23 CEST