On 17 Dec 2010, at 01:13, Mauricio Zambrano wrote: > Dear list, > > I need to change a value within a particular line of a plain text file > with characters and numbers, and I haven't found any way of doing this > by using R. > > What I have a is a file that doesn't have tabular data (so, I think > that 'read.table' or 'read.delim' are not the right tools for this), > but some text, and I now exactly the row that has to be modified and > the columns within that row that have to be changed with a new > numerical value. > > I don't' know any way of reading a text file line by line in R, and > this is the only solution in R that I have figured out so far... > > Any idea about how can I do this ?.
readLines will read lines from a flat file and create a character array: > list <- readLines("twelvedaysofchristmas.txt") > head(list) [1] "12 Drummers Drumming" "11 Pipers Piping" [3] "10 Lords-a-Leaping" "9 Ladies Dancing" [5] "8 Maids-a-Milking" "7 Swans-a-Swimming" You can either edit the line you want manually, or use sub to make changes: > sub("Lords-a-Leaping","Jaffa Cakes",list) > head(list) [1] "12 Drummers Drumming" "11 Pipers Piping" [3] "10 Jaffa Cakes" "9 Ladies Dancing" [5] "8 Maids-a-Milking" "7 Swans-a-Swimming" writeLines will write it back: > writeLines(list,"twelvedaysofchristmas.txt") Hope this helps, --t > > > Thanks in advance for any help, > > Mauricio > > -- > =============================== > Linux user #454569 -- Ubuntu user #17469 > > ______________________________________________ > 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. -- Thomson Van Nguyen Centre for Mathematical Studies University of Cambridge Wilberforce Road Cambridge CB3 0WA, UK Tel: +44 7597120422 E-mail: tn...@cam.ac.uk www.ocf.berkeley.edu/~thomson ______________________________________________ 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.