From gcr at wisdomandwonder.com  Sun Aug 10 20:18:21 2014
From: gcr at wisdomandwonder.com (Grant Rettke)
Date: Sun, 10 Aug 2014 13:18:21 -0500
Subject: [Rd] "Fastest" way to merge 300+ .5MB dataframes?
Message-ID: <CAAjq1mepNYOdWv5yOD_iM3-BC9Pyek2He0rudXOiKX+nDS8cJg@mail.gmail.com>

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
((? (x) (x x)) (? (x) (x x)))
?Life has become immeasurably better since I have been forced to stop
taking it seriously.? --Thompson



[Rd] "Fastest" way to merge 300+ .5MB dataframes?
Grant Rettke