Randomizing

[James Silverton]

Hello All!

I have been using a sort on a helper column of random numbers [generated
by RAND() ] to randomize a data set but I notice that the column of
random numbers changes when I do the sort. Can any expert tell me if the
sort or the recalculation occurs first?

--


James Silverton
Potomac, Maryland

Email, with obvious alterations:
not.jim.silverton.at.verizon.not

 

[Chip Pearson]

The sort comes first. You can see this by using a small list of data.
For example, in A1:A4 enter 1, 2, 3, and 4, and in B1:B4 enter
=RAND(). Next, copy the values in B1:B4 to D14. Copy/paste as
values only, not formulas. Now sort A14 by column B. You'll see that
the order of the elements in D are sorted, and then new values are
calculated in B. The new values in B are not (necessarily) in sorted
order, but values in D are.



Cordially,
Chip Pearson
Microsoft Most Valuable Professional,
Excel, 1998 - 2010
Pearson Software Consulting, LLC
www.cpearson.com

 

[James Silverton]

Chip wrote on Sat, 20 Mar 2010 10:14:11 -0500:

Cordially,
Chip Pearson
Microsoft Most Valuable Professional,
Excel, 1998 - 2010
Pearson Software Consulting, LLC
www.cpearson.com

On Sat, 20 Mar 2010 10:32:40 -0400, "James Silverton"

Hello All!

I have been using a sort on a helper column of random numbers
[generated by RAND() ] to randomize a data set but I notice
that the column of random numbers changes when I do the sort.
Can any expert tell me if the sort or the recalculation
occurs first?

The sort comes first. You can see this by using a small list of
data.......

Thanks, that's interesting.

--

James Silverton
Potomac, Maryland

Email, with obvious alterations: not.jim.silverton.at.verizon.not

 

[Mike H]

Hi,

The sort causes a recalculation so it comes after the sort takes place so
data will sort on the values you see in the helper column prior to the sort
taking place.

This can be verified by looking at the random numbers after the sort which
aren't in sorted order because they have changed.
--
Mike

When competing hypotheses are otherwise equal, adopt the hypothesis that
introduces the fewest assumptions while still sufficiently answering the
question.