On 13/10/2009 5:27 PM, Albert Vernon Smith wrote:
I am attempting to iterate over a file, processing it line by line. In my function below, I am only getting the first item over and over and over again from my test file rather than subsequent lines. How can I modify this to read lines sequentially?== iteratefile <- function(file) { f.con <- file(file) on.exit(close(f.con)) while( length(readln <- readLines(f.con, 1)) > 0 ) { x <- unlist(strsplit(readln, " ")) print(x[1]) } return(invisible()) } iteratefile("test.txt") == I am working with version 2.9.2 on Mac OS X 10.5. My code is based on examples I've taken from the mailing list, and I'm still only getting the top line. I'm not sure what I'm doing wrong.
You didn't open f.con at the start, so it gets reopened every time you call readLines. You should use
f.con <- file(file, open="rt") Duncan Murdoch ______________________________________________ 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.
