×
The internal search function is temporarily non-functional. The current search engine is no longer viable and we are researching alternatives.
As a stop gap measure, we are using Google's custom search engine service.
If you know of an easy to use, open source, search engine ... please contact support@midrange.com.
Wilt, Charles wrote:
IIRC every example I've seen about using _any_ built in random number function has
said basically, they return [0,1) or [0,1] and to get a number between a given range multiply by the
range. (IBM's SQL manual included!)
I couldn't tell from the SQL manual whether it was [0,1] or [0,1). It
can make rather a big difference, as we've seen, and it would be nice to
have it say explicitly.
So what is the "right" answer to using such a built in random number function?
Well, if the range of the RAND() function is [0,1), then I guess
floor( rand() * (n+1) )
would give an integer 0 <= x <= n. As Michael mentioned, if you want
the range to be 1 <= x <= n, then I think
floor(rand() * n) + 1
would work.
If the range of RAND() is [0,1], then I think that your solution to use
floor( rand() * (n+0.99999) )
would work well. My gut feeling is that it might throw off the
distribution at the top end a touch, but I can't really back that up
mathematically right now.
This mailing list archive is Copyright 1997-2024 by midrange.com and David Gibbs as a compilation work. Use of the archive is restricted to research of a business or technical nature. Any other uses are prohibited. Full details are available on our policy page. If you have questions about this, please contact
[javascript protected email address].
Operating expenses for this site are earned using the Amazon Associate program and Google Adsense.
midrange.com
