Statalist


[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

st: RE: Random seed revisited 2- how to get random seeds more efficiently?


From   "Tiago V. Pereira" <tiago.pereira@incor.usp.br>
To   statalist@hsphsun2.harvard.edu
Subject   st: RE: Random seed revisited 2- how to get random seeds more efficiently?
Date   Thu, 2 Oct 2008 14:01:01 -0300 (BRT)

Thank you so much for your excellent explanation, Bill!

-------------------------------------------------------------------
Bill wrote:

I'm confused by Tiago's question and I'm worried that it's not me that's
confused, but Tiago.  It sounds almost as if Tiago is resetting the seed
before generating each random number.  If so, Tiago does not want to do
that. -------------------------------------------------------------------

I thought it would be appropriate to add "a new pseudo-seed" inside the
loop because I need to do a loop, say, with 1000 replications, in which
each replication has then it own 1000 replications (e.g. a loop inside a
loop).

-------------------------------------------------------------------
Bill wrote:

Tiago worried that he is actually using the same seed for 2-5 loops. 
Right.That is a real, and obvious, problem.  But even if that were not the
case, there are problems awaiting us.  We have to worry that, in two
sequential resettings, given that seeds that are nearly equal, the first
random number drawn will be correlated with the preivous iteration's first
random number.
-------------------------------------------------------------------

Thatīs why my message is "how to get  random seeds more efficiently?".

Any other suggestions?

Thank you again for your time!

All the best,

Tiago








*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/



© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index