[solved itself] Which TRandom is default?

ROOT
1

edit: found the TObject::ClassName function and my question has solved itself. TRandom3 is default as documented, I just misinterpreted the output of the functions below.
But I still think its strange to use the name TRandom3 for the recommended generator instead of TRandom (which is even a bad one)

hi,
The Math documentation says that the TRandom3 is used:

[quote]TRandom3 is the recommended random number generator, and it is used by default in ROOT using the global
gRandom object (see chapter gRandom).[/quote]

but if i type [in trunk@28798]:

root [0] gRandom
(class TRandom*)0x9174438
root [1] gRandom->Class()->InheritsFrom("TRandom3")
(const Bool_t)0

Does this mean the linear congruential generator of TRandom is used?
If yes why is this so when that generator has quite serious flaws?

Also wouldn’t it be better to rename the recommended generator to TRandom instead of the bad one?
I know you can easily change it manually but it just seems more logical if the recommended generator is the default and has the most intuitive class name.

2

The default random generator gRandom is a TRandom3
see gRandom->ClassName() that gives you the effective class name.

TRandom is a 32 bit random number generator. As such it cannot be as good as TRandom3 (Mersenne Twister). However, it is wrong to say that TRandom is a bad generator (unless you are a real specialist of random number generators. TRandom3 should be used as the base for your event generator and you generate millions of events

Rene