[R] combining data from multiple read.delim() invocations.
pdalgd at gmail.com
Wed Jul 2 11:23:48 CEST 2014
On 01 Jul 2014, at 21:03 , John McKown <john.archie.mckown at gmail.com> wrote:
> Basically, a "wash". For a stress, I took in all 136 of my files in a
> single execution. Output was 22,823 elements in the data.frame.
> real 3m32.651s
> user 3m26.837s
> sys 0m2.292s
> real 3m24.603s
> user 3m20.225s
> sys 0m0.969s
> Still a wash. Of course, since I run this only once a week, on a Sunday,
> the time is not too important. I actually think that your solution is a bit
> more readable than mine. So long as I document what is going on.
One rbind() should actually be faster than using 136 rbind() calls while expanding the data frame on each iteration. Presumably, most of the time is spent elsewhere, but 8s in the opposite direction is a little surprising. You might want to check the timing of just the
df.all <- do.call(rbind, df.list)
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Email: pd.mes at cbs.dk Priv: PDalgd at gmail.com
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