[Rd] "Fastest" way to merge 300+ .5MB dataframes?
gcr at wisdomandwonder.com
Sun Aug 10 20:49:33 CEST 2014
My sincere apologies.
Having read http://www.r-project.org/posting-guide.html , I had wanted
to post this one to R-help.
Grant Rettke | ACM, ASA, FSF, IEEE, SIAM
gcr at wisdomandwonder.com | http://www.wisdomandwonder.com/
“Wisdom begins in wonder.” --Socrates
((λ (x) (x x)) (λ (x) (x x)))
“Life has become immeasurably better since I have been forced to stop
taking it seriously.” --Thompson
On Sun, Aug 10, 2014 at 1:28 PM, Joshua Ulrich <josh.m.ulrich at gmail.com> wrote:
> The same comment Jeroen Ooms made about your last email also applies
> to this one: it is better suited to R-help.
> Joshua Ulrich | about.me/joshuaulrich
> FOSS Trading | www.fosstrading.com
> On Sun, Aug 10, 2014 at 1:18 PM, Grant Rettke <gcr at wisdomandwonder.com> wrote:
>> Good afternoon,
>> Today I was working on a practice problem. It was simple, and perhaps
>> even realistic. It looked like this:
>> • Get a list of all the data files in a directory
>> • Load each file into a dataframe
>> • Merge them into a single data frame
>> Because all of the columns were the same, the simplest solution in my
>> mind was to `Reduce' the vector of dataframes with a call to
>> `merge'. That worked fine, I got what was expected. That is key
>> actually. It is literally a one-liner, and there will never be index
>> or scoping errors with it.
>> Now with that in mind, what is the idiomatic way? Do people usually do
>> something else because it is /faster/ (by some definition)?
>> Kind regards,
>> Grant Rettke | ACM, ASA, FSF, IEEE, SIAM
>> gcr at wisdomandwonder.com | http://www.wisdomandwonder.com/
>> “Wisdom begins in wonder.” --Socrates
>> ((λ (x) (x x)) (λ (x) (x x)))
>> “Life has become immeasurably better since I have been forced to stop
>> taking it seriously.” --Thompson
>> R-devel at r-project.org mailing list
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