# st: Using results from correlation matrices to pinpoint variables

 From Alejandro Delafuente <[email protected]> To [email protected] Subject st: Using results from correlation matrices to pinpoint variables Date Thu, 16 Jun 2005 17:49:20 +0100 (BST)

Dear Statalisters,
I am running several correlations between a set of core variables (v1 v2 v3)
and a list of other variables (v4 to v60). Once each correlation is run, I
want Stata to select a variable from my core group if it satisfies two
conditions: a) has the highest correlation coefficient among all (always
plausible to find one), and b) have a coefficient above >.75. Thus, in my
example below v2 would be the variable that i want. I don't know how to tell
Stata to look for the variable when both conditions are met, and then use it
for other purposes (ie, create a means ratio where the denominator would be the
time mean for the selected variable), or do nothing when this is not the case.
My subprogram below the correlation matrix is just to clarify my goal. I don't
know if saving the matrix after each correlation and then referring to the
outputs of the first column would be a possible way to pinpoint my variable.
Any help on how to program this (if possible) would be very much appreciated.

corr v4 \$othervars if _n>10
(obs=162)

|       v4       v1       v2       v3
-------------+------------------------------------
v4 |   1.0000
v1 |   0.6307   1.0000
v2 |   0.8028   0.7753   1.0000
v3 |   0.7045   0.4304   0.5670   1.0000

forvalues i = 1/60 {
corr v`i' `othervars' //`othervars' includes v1 v2 and v3
gen ratio`i'=v`i' / x
// if x has the highest correlation with v`i' & corr>.75 // here v2

Many thanks!

Alejandro

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