Generating Random numbers.

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Tyler - 22 Sep 2007 21:08 GMT

I need to generate a set of random numbers. I know there is a way to do this;
I just do not know how to find it. Please help me

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joeu2004 - 22 Sep 2007 21:31 GMT

> I need to generate a set of random numbers. I know there is a way
> to do this; I just do not know how to find it. Please help me

That depends on your constaints. Generally, to generate random
numbers with a uniform distribution, use the RAND() function in Excel
or the Rnd() function in VBA. If you want randoms integers between A
and B inclusive, again uniformly distributed, you can use the
following formula:

=A + int((B-A)*rand())

Alternativley, you can use RANDBETWEEN(), which is in the Analysis
ToolPak.

However, different techniques may be needed if you want something
other than a uniform distribution.

Moreover, some addition attention is needed if you want to avoid
duplicate random numbers.

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joeu2004 - 22 Sep 2007 21:43 GMT

Errata....

On Sep 22, 1:31 pm, I wrote:

> If you want randoms integers between A and B inclusive,
> again uniformly distributed, you can use the following formula:
> =A + int((B-A)*rand())

I believe that should be either of the following formulas:

=A + round((B-A)*rand(), 0)

=A + int((B-A+1)*rand())

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Gord Dibben - 22 Sep 2007 21:48 GMT

See help on RAND function.

Basic usage...............

In A1 enter = RAND() and copy down as far as you wish.

You may get duplicates using this method.

See John McGimpsey's site for Random numbers with no duplicates.

http://www.mcgimpsey.com/excel/udfs/randint.html

Gord Dibben MS Excel MVP

>I need to generate a set of random numbers. I know there is a way to do this;
>I just do not know how to find it. Please help me

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