Pasha Murat wrote: > > > Hello, > I feel that I am missing something in the discussion above so I'd > appreciate to be given a clarification. Let me explain what exactly I'm > missing: > > - what `hrndm1' does it returns a *single* random number distributed > according a probability distribution stored in a given histogram. > - `FillRandom' methods do very different thing - they *fill a histogram* > according to a given probability density stored elsewhere, therefore it seems > to me that they miss functionality of `hrndm1' which is quite often needed by > the users. > > So is it possible to generate (and retrieve!) a single random number (set of > numbers) which probability density is stored in a given histogram ? > Currently the following functions are provided -TF1::GetRandom returns one number at the time from a theoretical function.Note that TF1::GetRandom uses the real integral of the function and not just the sum of the function precomputed for some bins as it was the case in Hbook for example. -TH1::FillRandom(TF1 *) generates a bunch of random numbers from a theoretical function (1-d,2-d,3-d) and fill an histogram -TH1::FillRandom(TH1 *) generates a bunch of random numbers from a histogram (1-d,2-d or 3-d) and fill a histogram. I could provide a TH1::GetRandom or similar for 2-d and 3-d. To do that, I must store the integral of the bin contents somewhere as it is out of question to recompute this integral at every call like in TH1::FillRandom. I will add this item to my list. Rene Brun
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