Best Method
in [Programming]
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From: Chip Pearson on 15 Mar 2010 08:57 See http://www.cpearson.com/excel/RandomNumbers.aspx for code for generating a set of random longs between a lower and upper bound, either with repetition or without repetition. Cordially, Chip Pearson Microsoft Most Valuable Professional, Excel, 1998 - 2010 Pearson Software Consulting, LLC www.cpearson.com On Sun, 14 Mar 2010 16:14:09 -0700, "Dennis Tucker" <dennis13030(a)cox.net> wrote: >What is the best method to make a list of randomized(non-repeating) numbers between a start value and a end value?
From: Neal Zimm on 16 Mar 2010 17:36 Dennis, I'm just a bystander here, but from an app point of view, If you want random numbers, Why do they have to be non- repeating ? Guessing that you're not really after a random number at all. The msoft help on the Rnd function tells how to generate the "same" sequence of random numbers (if needed) but there's no guarantee the a provided number won't be the same as the one previously generated. -- Neal Z "Dennis Tucker" wrote: > What is the best method to make a list of randomized(non-repeating) numbers between a start value and a end value? > >
From: Jef Gorbach on 16 Mar 2010 17:48 On Mar 16, 5:36 pm, Neal Zimm <nealz...(a)yahoo.com> wrote: > Dennis, > I'm just a bystander here, but from an app point of view, If you want > random numbers, Why do they have to be non- repeating ? Guessing that > you're not really after a random number at all. > For those situations where you need to randomly draw from a fixed number of unique items, which once drawn cant be reused/repeated -- like randomly assigning people to teams, bingo numbers, etc.
From: helene and gabor on 17 Mar 2010 08:04 Hello, =randbetween(1,36) will for example generate random integers from 1 to 36. When you copy this formula down along a column, you could have as many such numbers as you want. You can then copy this column to another set of cells and use: Remove Duplicates feature of Excel 2007. Good Luck! Gabor Sebo ----- Original Message ----- From: Dennis Tucker Newsgroups: microsoft.public.excel.programming Sent: Sunday, March 14, 2010 7:14 PM Subject: Best Method What is the best method to make a list of randomized(non-repeating) numbers between a start value and a end value? "Dennis Tucker" <dennis13030(a)cox.net> wrote in message news:%23ZbJHw8wKHA.812(a)TK2MSFTNGP06.phx.gbl... What is the best method to make a list of randomized(non-repeating) numbers between a start value and a end value?
From: Dana DeLouis on 19 Mar 2010 00:54
On 3/14/2010 7:14 PM, Dennis Tucker wrote: > What is the best method to make a list of randomized(non-repeating) > numbers between a start value and a end value? Hi. Just as a side note, the "Best Method" may 'depend' on your size also. Most algorithms first generate all numbers, then pick unique values. However, this may be impractical if you have to pick from a size of 1 million. Not quite what I use, but an algorithm may want to branch off and do something like this if you had to pick 6 numbers from 10,000,000 Sub Demo() [A1:A6] = WorksheetFunction.Transpose(RandomSample(6, 1, 10000000)) End Sub Function RandomSample(n, L, H) Dim d Dim x Set d = CreateObject("Scripting.Dictionary") Do While d.Count < n x = Int(Rnd * (H - L + 1)) + L If Not d.exists(x) Then d.Add x, x Loop RandomSample = d.keys End Function However, your main program would not want to call this routine if you wanted to pick 100 numbers out of 100. The program would have to loop, on average, 518 times. Hence, the above would not be efficient. = = = = = = = HTH :>) Dana DeLouis |