Help! I have a very large data file with about 100 columns. Instead of loading all of the columns using read.table() (my PC won't be able to handle the resulting data frame), I'd like to read in one column of the datafile at a time using scan() in conjunction with the 'what = ' option. I've tried loading just the third column using -> scan(file.name, what = list(NULL, NULL, "", rep(NULL, 97)). ... )along with a couple of other options but I can't get the results I want (if I avoid an error). For example -> list(NULL, NULL, "", rep(NULL, 97))[[1]] NULL [[2]] NULL [[3]] [1] "" [[4]] NULL is not what i'm looking for. Is there a better way to selectively read in individual columns from a tab separated data file? I've done this before, and that makes this exercise even more frustrating. Thanks in advance. Samir Mishra ==========================================Please send replies to : sqmishra at acm.org ========================================== _______________________________________________________ Send a cool gift with your E-Card http://www.bluemountain.com/giftcenter/ -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- 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 _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
On Sun, 7 Jan 2001, Samir Mishra wrote:> Help! > > I have a very large data file with about 100 columns. Instead of loading > all of the columns using read.table() (my PC won't be able to handle the > resulting data frame), I'd like to read in one column of the datafile at > a time using scan() in conjunction with the 'what = ' option. I've tried > loading just the third column using - > > > scan(file.name, what = list(NULL, NULL, "", rep(NULL, 97)). ... ) > > along with a couple of other options but I can't get the results I want > (if I avoid an error). For example - > > list(NULL, NULL, "", rep(NULL, 97)) > [[1]] > NULL > > [[2]] > NULL > > [[3]] > [1] "" > > [[4]] > NULL > > is not what i'm looking for. > > Is there a better way to selectively read in individual columns from a tab > separated data file? > > I've done this before, and that makes this exercise even more frustrating.Try scan(file.name, what = list(, , ""), flush = TRUE) Uwe Ligges -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- 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 _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._