Thanks Charles for this reply. I have started according to your suggestion and hopefully I can do it. In the mean time what I was thinking, instead of calling my text files by their names, is there any mechanism to call them by the order they are stored in that directory? Means, suppose, I have total 1000 text files in that directory and therefore I create a vector like sel.no <- c(1:1000). Next I use the i-th element of the vector "sel.no" to access the i-th file?
With regards, Charles C. Berry wrote: > > On Mon, 15 Dec 2008, megh wrote: > >> >> Hi all, >> >> I my c: drive I have possibly 1,000 notepad files, with .txt extension. >> They >> are named as the dates on which they were saved i.e. 1st file name is >> "Volume_4-18-2008", 2nd one is "Volume_4-21-2008", 3rd one >> "Volume_4-22-2008" and so on............ >> >> Also, content of each file are in same format like : >> >> ******** content of 1st file ************* >> section : 1 >> ----- --------- ---------- ----------- >> ----- --------- ---------- ----------- >> ----- --------- ---------- ----------- >> ----- --------- ---------- ----------- >> section : 2 >> ----- --------- ---------- ----------- >> ----- --------- ---------- ----------- >> ----- --------- ---------- ----------- >> ----- --------- ---------- ----------- >> section : 3 >> ----- --------- ---------- ----------- >> ----- --------- ---------- ----------- >> ----- --------- ---------- ----------- >> ----- --------- ---------- ----------- >> section : 4 >> ----- --------- ---------- ----------- >> ----- --------- ---------- ----------- >> ----- --------- ---------- ----------- >> ----- --------- ---------- ----------- >> >> Here all files have 4-sections, just like shown here but contents within >> each section (i.e. dashed line here) differs file to file. >> >> What I have to do is I have to fetch contents of "section : 2" from each >> file and then save it to a R-object, matrix of list for further analysis. >> >> Can you ppl please tell me how to do that? > > Here is the outline: > > *) use list.files() or Sys.glob() to get a list of the files > > *) write a function that takes the file name as its arg, uses > readLines() to swallow the text and uses grep() to find the > 'section' lines. Then put the 'dashes' in between two section > lines into a separate object (say, dash.lines). Then use > > as.matrix( read.table(con <- textConnection( dash.lines ) ) > close(con) > > to get the numeric values or maybe > > sapply( strsplit(dash.lines, "[ ]+"), as.numeric) > > *) debug this on one file > > > *) use lapply to step thru the list of file names. > > See > > ?list.files > ?Sys.glob > ?readLines > ?grep > ?textConnection > ?strsplit > ?sapply > > HTH, > > Chuck > > >> >> Thanks and regards, >> -- >> View this message in context: >> http://www.nabble.com/How-to-fetch-specific-part-from-a-number-of-Text-files--tp21011017p21011017.html >> Sent from the R help mailing list archive at Nabble.com. >> >> ______________________________________________ >> R-help@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. >> > > Charles C. Berry (858) 534-2098 > Dept of Family/Preventive > Medicine > E mailto:cbe...@tajo.ucsd.edu UC San Diego > http://famprevmed.ucsd.edu/faculty/cberry/ La Jolla, San Diego 92093-0901 > > ______________________________________________ > R-help@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. > > -- View this message in context: http://www.nabble.com/How-to-fetch-specific-part-from-a-number-of-Text-files--tp21011017p21020032.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@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.