Re: [R] how to test robustness of correlation

2006-01-26 Thread Berton Gunter
the statistician is to catalyze the scientific learning process." - George E. P. Box > -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Gabor > Grothendieck > Sent: Thursday, January 26, 2006 9:05 AM > To: [EMAIL PROTECTED] &g

Re: [R] how to test robustness of correlation

2006-01-26 Thread Gabor Grothendieck
The cor function can do spearman correlation using method = "spearman" . On 1/25/06, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote: > Hi, there: > > As you all know, correlation is not a very robust procedure. Sometimes > correlation could be driven by a few outliers. There are a few ways to > impr

Re: [R] how to test robustness of correlation

2006-01-26 Thread Berton Gunter
One more thing ... > I played around cor.rob(). Yes, I can get a robust correlation > coefficient matrix based on mcd or mve outlier detection methods. > > I have two further questions: > You might call it semantics, but I prefer "resistant estimation" to "outlier detection methods." I rec

Re: [R] how to test robustness of correlation

2006-01-26 Thread Berton Gunter
Below > > Hi, Berton: > thanks for getting back to me. > > I played around cor.rob(). Yes, I can get a robust > correlation coefficient matrix based on mcd or mve outlier > detection methods. > > I have two further questions: > > 1) How do I get a p value of the robust r? A p-valu

Re: [R] how to test robustness of correlation

2006-01-26 Thread yang . x . qiu
[EMAIL PROTECTED], r-help@stat.math.ethz.ch cc Subject RE: [R] how to test robustness of correlation check out cov.rob() in MASS (among others, I'm sure). The procedure is far more sophisticated than "outlier removal" or resampling (??). References are given in the docs. -- Bert Gunter Ge

Re: [R] how to test robustness of correlation

2006-01-25 Thread Berton Gunter
ician is to catalyze the scientific learning process." - George E. P. Box > -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of > [EMAIL PROTECTED] > Sent: Wednesday, January 25, 2006 12:37 PM > To: r-help@stat.math.ethz.

[R] how to test robustness of correlation

2006-01-25 Thread yang . x . qiu
Hi, there: As you all know, correlation is not a very robust procedure. Sometimes correlation could be driven by a few outliers. There are a few ways to improve the robustness of correlation (pearson correlation), either by outlier removal procedure, or resampling technique. I am wondering i