[R] a loop to chang data matrix name

[Peter Dalgaard BSA]

Yu-Ling Wu <yuling5 at yahoo.com> writes:

> Hi,
> 
> I have 50 data matrix x1 ~ x5. I want to write a loop
> to check the number of 
> rows for each data matrix. How to make the data matrix
> name (numerical part)
> increase by 1 each time it loops?
> 
> That is, 
> loop1:  nrow(x1)
> loop2: nrow(x2)
> ....
> loop50: nrow(x50)
> 
> ---------------------------------------------------------------
> for (i in 1:50) {
>    if nrow( xi ) > 20    <=== how to make this work?
>       do someting ......
> }
> --------------------------------------------------------------

With a bit more experience, you could probably ensure that your
matrices were in a list to begin with instead of having information
encoded in their name, but try

 for (xi in paste("x",1:50,sep="") {
    if (nrow( get(xi) ) > 20 )
       do someting ......
 }


-- 
   O__  ---- Peter Dalgaard             Blegdamsvej 3  
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
 (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)             FAX: (+45) 35327907
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-help-request at stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._