[R] variables in a correlation matrix

[ripley@stats.ox.ac.uk]

On Wed, 12 Mar 2003, juli g. pausas wrote:

> Hi,
> Given a correlation matrix, how can I know which variables have certain 
> correlation values?
> 
> aa <- matrix( rnorm(25, 1,1), 5,5)
> colnames(aa) <- c("v1", "v2", "v3", "v4", "v5")
> aacor <- cor(aa)
> 
> For instance, which variables are negatively correlated?    
> aacor[aacor<0]  # provide the r values, but how I get the variables?

nm <- dimnames(aacor)[[1]]
cbind(nm[row(aacor)[aacor<0]], nm[col(aacor)[aacor<0]])

is one way

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
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