[R] Mahalanobis distance

From: yoo hoo <freesuccess2001_at_yahoo.com>
Date: Tue, 22 Jun 2010 14:41:23 -0700 (PDT)


I am a new R user. i have a question about Mahalanobis distance.actually i have 300 rows and 7 columns. columns are different measurements, 300 rows are genes. since genes can classify into 4 categories. i used dist() with euclidean distance and cmdscale to do MDS plot. but find out Mahalanobis distance may be better. how do i use Mahalanobis() to generate similar dist object which i can use MDS plot? second question is if should i calculate mean for every categories for every measurement first and do 4*4 distance matrix, or i should calculate pairwise distance first and then find category means since i only care about relative position of 4 categories in MDS plot. Thank you very much.

      
	[[alternative HTML version deleted]]

______________________________________________
R-help_at_r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. Received on Wed 23 Jun 2010 - 00:16:07 GMT

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Wed 23 Jun 2010 - 02:00:34 GMT.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help. Please read the posting guide before posting to the list.

list of date sections of archive