[R] Fast way to determine number of lines in a file
hb at stat.berkeley.edu
Mon Feb 8 16:21:34 CET 2010
I was looking for a fast line counter as well a while ago and ended up
writing a small function in R:
countLines() in the R.utils package
At least at the time, it was faster than readLines() [for unknown
reasons]. It is also more memory efficient. It supports connections.
I don't think it beats a system call to 'wc', though. When there
will be a faster solution available, it'll be calling that instead.
It does not avoid reading the file twice.
On Mon, Feb 8, 2010 at 4:17 PM, hadley wickham <h.wickham at gmail.com> wrote:
> Hi Ken,
>> How about something like
> I'm trying to avoid the overhead of reading the file in twice. (I'm
> trying to preallocate a data structure for a chunked read)
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