Re: [R] var-covar matrices comparison

2006-02-22 Thread Peter Dalgaard
David Duffy <[EMAIL PROTECTED]> writes: > > Date: Mon, 20 Feb 2006 16:43:55 -0600 > > From: Aldi Kraja <[EMAIL PROTECTED]> > > > > Hi, > > Using package gclus in R, I have created some graphs that show the > > trends within subgroups of data and correlations among 9 variables (v1-v9). > > Being in

Re: [R] var-covar matrices comparison

2006-02-21 Thread David Duffy
> Date: Mon, 20 Feb 2006 16:43:55 -0600 > From: Aldi Kraja <[EMAIL PROTECTED]> > > Hi, > Using package gclus in R, I have created some graphs that show the > trends within subgroups of data and correlations among 9 variables (v1-v9). > Being interested for more details on these data I have produced

Re: [R] var-covar matrices comparison:

2006-02-21 Thread Aldi Kraja
Thank you Patrick for your thoughts. I was expecting someone had written a function that does maybe a hierarchical comparison of var-covar matrices using the flury hierarchy as proposed by Philips and Arnold in Evolution 53(5), 1999;1506-1515. But your email has an interesting idea, so I will t

Re: [R] var-covar matrices comparison:

2006-02-21 Thread Patrick Burns
My first thought is to use a random permutation test. In this setting the main question you need to ask is what distance measure do you want to use between variance matrices -- there are lots of choices. One that I've found useful is the absolute value of the maximum eigenvalue of the difference o

[R] var-covar matrices comparison:

2006-02-20 Thread Aldi Kraja
Hi, Using package gclus in R, I have created some graphs that show the trends within subgroups of data and correlations among 9 variables (v1-v9). Being interested for more details on these data I have produced also the var-covar matrices. Question: From a pair of two subsets of data (with 9 vari