TRandom Documentation

Dear Rooters,

in the Documentation for the TRandom, the default ctor has only the following documentation:

while in TRandom3 the same ctor reads

The functionality, however, is the same. Could the second statement also be included in the TRandom documentation as it is the natural starting point to look into TRandom functionality?

Furthermore, the example given in the documentation

will give exactly the same sequence for both TRandom objects if the function call is the same (e.g. TRandom::Gaus() ). At the end of the example it is stated that

but not that one indeed should do this if the function call is the same because by default both TRandom objects will have the same seed if called as above.

Correct me if I am missing something.

Best regards,



thank you for your comments. I agree the documentation of TRandom constructor is missing in the reference doc.
It should be stressed however that users should not instantiates instances of TRandom, since the generator has bad random quality and the sequences repeats itself after only generating 10^9 numbers (which can be done in just few seconds).
Also the initialization of TRandom is different when calling with a 0 value than TRandom3. TRandom3 using a TUUID which is a unique number, while this not the case for TRandom. The seed is generate just simply using the current time.

I will update in the next days the doc taking into account your suggestions,
Best Regards