generate unique random numbers

  • Thread starter Thread starter Stephen Larivee
  • Start date Start date
S

Stephen Larivee

I have a list of 600 names. I would like to generate a random number
between 1 and 600 for each person but not have any repeating numbers. So
far I have used
=rand()*600
This give me the correct number range but many of the numbers repeat.

Can I accomplish what I want to do?
 
One way ..

Suppose serial nos (1,2,3 ... 600)
and names are in cols A and B, from row1 to 600

Put in C1: =INDEX($A$1:$A$600,RANK(D1,$D$1:$D$600))
Put in D1: =RAND()
Select C1:D1, fill down

C1 returns the random shuffle of the serial nos that's required
Press F9 key to regenerate
 
Thank you!!!!! I will give it a try.


Max said:
One way ..

Suppose serial nos (1,2,3 ... 600)
and names are in cols A and B, from row1 to 600

Put in C1: =INDEX($A$1:$A$600,RANK(D1,$D$1:$D$600))
Put in D1: =RAND()
Select C1:D1, fill down

C1 returns the random shuffle of the serial nos that's required
Press F9 key to regenerate
Click to expand...
 
My mistake. I made an error in the formula. I corrected it and it seems to
be doing just what I wanted. Thank you very much.
 
Alternatively, get PopTools, a free add-in (Google will turn it up).
Among many very-well implemented variate generators are a host of other
functions. Among them is Shuffle. Here's how you can also keep location
and sizes of your lists more manageable:
Enter 1 through 600 (or whatever) into a column; it might be, say, in
C3:C602. Insert>Name>Define that range as Indexes. Into another column,
say D3:D602, enter your list of names, and Insert>Name>Define it as
NameList. Into E3:E602, array-enter (ctrl-shift-enter)
=Shuffle(Indexes), and name it ShuffledIndexes. Finally, into F3:F602,
array-enter =INDEX(NameList,ShuffledIndexes)

I mention this in part because PopTools's Shuffle command draws without
replacement, a handy thing to have. It has a lot of other excellent
stuff, and it's free!!!

HTH
Dave Braden
 
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