Re: Retrieving of TF1 precompiled function

Rene Brun (Rene.Brun@cern.ch)
Mon, 07 Jun 1999 14:06:12 +0000

Hi Boris,
In case of precompiled TF1 functions, Root, by definition, cannot save
the
precompiled function on the file. However, it is possible to tabulate
the function and save the table together with the function.
This table was already automatically computed/filled during a TF1::Fit.
I have extended this possibility to save the tabulated function as soon
as
one writes such a function on a file. The change will appear in 2.22/05.

Rene Brun

polishchuk_at_mx.ihep.su wrote:
>
> Dear Rooters,
>
> is it possible to retrieve TF1 precompiled function ("type C")
> from ROOT file? There's no problem with TF1 "class A" and "class B".
> But what I obtained with function f1int from $ROOTSYS/test/stress.root:
>
> root [1] TFile f("stress.root");
> root [2] f1int.Print()
> f1int : Ndim= 0, Npar= 9, Noper= 0
> Par 0 p0 = 224.9
> Par 1 p1 = -2.92761
> Par 2 p2 = 3.02638
> Par 3 p3 = 134.141
> Par 4 p4 = -0.0224946
> Par 5 p5 = 0.496904
> Par 6 p6 = 83.9318
> Par 7 p7 = 4.00135
> Par 8 p8 = 0.633848
> TH1.Print Name= Func, Total sum= 0
>
> root [8] f1int.Eval(1)
> (Double_t)0.000000000000e+00
> root [9] f1int.Eval(100)
> (Double_t)0.000000000000e+00
> root [10] f1int.Eval(-3.14)
> (Double_t)0.000000000000e+00
>
> - it is zero everywhere.
>
> Best regards,
> Boris Polishchuk