On Mar 31, 5:29*am, hdf <(E-Mail Removed)> wrote:

> I know how to generate two sets of random correlated

> variables
What do you mean by that? Do you mean that you know how to generate

two random sets of data and compute their correlation? Or do you mean

that you know how to generate one random set of data and generate

another data set over a different range of numbers that is exactly

correlated (non-random)?

An example would help clarify your meaning.

You wrote:

> To be clear, I have a column of values ranging from

> 100 to 175. *I want to generate a second column of random

> variables (-1 to 1) which are correlated with this column,

> to whatever correlation coefficient I choose.
Few things are "impossible" to do with computers. It depends on how

long you are willing to wait for a solution.

Off-hand, if I understand your requirements correctly, I believe this

is a very difficult task to accomplish in a reasonable finite amount

of time. The troubleshome requirement is "whatever correlation

coefficient I choose".

You could generate n-1 random values in the range [-1,1], then solve

for the n-th value that gives the required correlation coefficient.

Even that might be difficult due to the nature of the correlation

formula, if you use the same one as that found on the Excel CORREL

help page.

Moreover, there is no guarantee that the n-th value that meets the

correlation requirement will be in the range [-1,1].

Of course, you can always generate n random values in the range [-1,1]

repeatedly until you stumble upon a set that meets your criteria. But

such repetition can take a long time, and there is no guarantee of

"ever" finding a solution in your lifetime.

For additional ideas and broader participation, you might want to

repost your inquiry using the MS Answers Forums at

http://social.answers.microsoft.com/...ry/officeexcel.

It's not that I like that forum. It's just that MS has ceased to

support the Usenet newsgroups; see

http://www.microsoft.com/communities...s/default.mspx.

Hence, participation here is limited to the sites that share a common

newsgroup mirror, which is no longer centralized at MS. Many of the

diehard contributors no longer pay attention to the Usenet newsgroups.