List of valid random generators

[cmiller]

Is there a list of valid generators that can be called for a TH1? in all the examples I can find only “gaus” is used

TH1F* h1 =new TH1F();
h1->FillRandom("gaus",1000);

The TRandom class reference suggests there’s others that can be called but doesn’t seem to list the names that FillRandom will accept

update:
I dug into the source code and tracked the predefined functions back to line 2488 of TF1.cxx. But the question of are these functions listed anywhere in the documentation still remains

[Wile_E_Coyote]

TH1::FillRandom can be used to randomly fill an histogram using the contents of an existing TF1 function or another TH1 histogram (for all dimensions).

[cmiller]

I never defined the “gaus” function above, so it’s predefined somewhere. But I can’t find a list of the predefined function names, except in the source code

[Wile_E_Coyote]

((TF1*)gROOT->GetFunction("gaus"))->Print();
gROOT->GetListOfFunctions()->ls();

[cmiller]

Thanks, That worked. Are the functions listed in the documentation anywhere? Or is this the only way to find them?

[Wile_E_Coyote]

You can define your own TF1 functions.

[cmiller]

yes i could. but if i want to quickly test something it’s easier to just use the predefined functions and in for the case i’m testing now I needed 2. I was just trying to find a list of the predefined functions in the documentation. Does it exist?

[Wile_E_Coyote]

TF1::InitStandardFunctions();
gROOT->GetListOfFunctions()->ls();

[cmiller]

@couet I mean in the documentation. Like in the tf1 or th1 class reference. Somewhere that doesn’t require a user to know a specific command

[couet]

@moneta will know better which part of the documentation should be updated.

[moneta]

Hi,
We should probably update the TF1 reference documentation with the list of predefined functions which are created calling TF1::InitStandardFunctions() and then available globally in the functionalist of TROOT ( `gROOT->getListOfFunctions() ).
We should add a link to the documentation of the predefined functions also in the reference doc of TROOT.

In addition, I see that TF1::InitStandardFunctions() is called automatically when calling TROOT::GetFunction(name). We should probably called it also when the users just asks for TROOT::GetListOfFunctions()

Lorenzo