[R] Computing the rank of a matrix.

Charilaos Skiadas skiadas at hanover.edu
Fri Apr 6 13:50:13 CEST 2007


On Apr 6, 2007, at 7:39 AM, José Luis Aznarte M. wrote:

>     Hi! Maybe this is a silly question, but I need the column rank
> (http://en.wikipedia.org/wiki/Rank_matrix) of a matrix and R function
> 'rank()' only gives me the ordering of the elements of my matrix.
>     How can I compute the column rank of a matrix? Is there not an R
> equivalent to Matlab's 'rank()'?
>     I've been browsing for a time now and I can't find anything, so  
> any
> help will be greatly appreciated. Best regards!
>
Surprisingly, google searching for "r matrix rank" actually returns a  
R link:

http://tolstoy.newcastle.edu.au/R/help/05/05/4000.html

I suppose the point is that in R you usually need a bit more than  
just the rank, so instead you want an object that contains all that  
info and more. Like we have the various lm objects, so to speak. They  
do the hard work once, and then we can ask them more particular  
questions.

?qr

> --                                                      --
> Jose Luis Aznarte M.       http://decsai.ugr.es/~jlaznarte
> Department of Computer Science and Artificial Intelligence
> Universidad de Granada           Tel. +34 - 958 - 24 04 67
> GRANADA (Spain)                  Fax: +34 - 958 - 24 00 79

Haris Skiadas
Department of Mathematics and Computer Science
Hanover College



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