[R] Searching for specific values in a matrix

[Steve Lianoglou]

Hi,

On Jul 21, 2009, at 1:47 PM, Mehdi Khan wrote:

> Hello all,
>
> I have a seemingly simple question which I have searched for an  
> answer for
> for a few hours without luck.  I have a matrix of both values and  
> characters
> with thousands of rows.  I would like to run a search of this matrix  
> for
> certain values and would like the search to retrieve the entire  
> row.  How
> would I accomplish this?

Are the characters and values (numeric, I guess(?)) in their own  
respective columns? If so, make sure you use a data frame.

That having been said:

R> df <- data.frame(nums=1:10, words=c("Abelonian",
     "abeltree",
     "Abencerrages",
     "abenteric",
     "abepithymia",
     "Aberdeen",
     "aberdevine",
     "Aberdonian",
     "Aberia",
     "aberrance"))
R> idxs <- grep('ia', df$words)
R> df[idxs,]
   nums       words
1    1   Abelonian
5    5 abepithymia
8    8  Aberdonian
9    9      Aberia

Is something like that what you're after?

-steve

--
Steve Lianoglou
Graduate Student: Physiology, Biophysics and Systems Biology
Weill Medical College of Cornell University

Contact Info: http://cbio.mskcc.org/~lianos/contact