On 22-Sep-08 11:00:30, José E. Lozano wrote: >> So is each line just ACCGTATAT etc etc? > > Exacty, A_G, A_A, G_G and the such. > >> If you have fixed width fields in a file, so that every line is the >> same length, then you can use random access methods to get to a >> particular value - just multiply the line length by the row number you > > Nice hint! I didnt think on this. But I fear that if I have missing > values on the file I wont be able to read the right information... > >> When doing this, it's a good idea to test your dataset first to make >> sure the lines and fields are right. > > Yes, I am trying to figure out if all the lines have the exact same > lenght to use a random access method to read it.
If you were using Linux, I would suggest a command on the lines of cat filename | awk '{print(length($0))}' which would give you the length of each line. But since you have around 2000 lines, to simply check whether they all have the same length (in bytes/characters) you can extend the above to cat filename | awk '{print(length($0))}' | sort -u which will present you with all the different line-lengths. If they are all the same length you will get one number. I just tested this on a file with lines exceeding 500,000 characters in length, and it worked perfectly well even for such long lines. Ted. -------------------------------------------------------------------- E-Mail: (Ted Harding) <[EMAIL PROTECTED]> Fax-to-email: +44 (0)870 094 0861 Date: 22-Sep-08 Time: 17:03:21 ------------------------------ XFMail ------------------------------ ______________________________________________ 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.