No, you don't have to use four dots. Please check these links for further details:
http://stackoverflow.com/questions/5890576/usage-of-three-dots-or-dot-dot-dot-in-functions http://cran.r-project.org/doc/manuals/R-lang.pdf A.K. ________________________________ From: Janesh Devkota <janesh.devk...@gmail.com> To: arun <smartpink...@yahoo.com> Cc: R help <r-help@r-project.org>; Farnoosh <farnoosh...@yahoo.com> Sent: Wednesday, April 17, 2013 1:23 PM Subject: Re: [R] Merge Hello Arun, Thank you so much for the prompt reply. I have one simple question here. DOes three dots (...) in the reduce function means we are applying for three dataframes here ? So, if we were to combine four would that dots be four dots ? Thanks. On Wed, Apr 17, 2013 at 12:16 PM, arun <smartpink...@yahoo.com> wrote: > >HI Janesh, > >YOu can use: >library(plyr) >?join_all() > >#From the help page: > > dfs <- list( > a = data.frame(x = 1:10, a = runif(10)), > b = data.frame(x = 1:10, b = runif(10)), > c = data.frame(x = 1:10, c = runif(10)) > ) > join_all(dfs) > join_all(dfs, "x") > > join_all(dfs, "x") ># x a b c >#1 1 0.7113766 0.1348978 0.1153703 >#2 2 0.2520057 0.7249154 0.2362936 >#3 3 0.5670157 0.8166805 0.3049683 >#4 4 0.7441726 0.4929165 0.6779029 >#5 5 0.5616914 0.5272339 0.6202915 >#6 6 0.2858429 0.1203205 0.8399356 >#7 7 0.9910520 0.1251815 0.4729418 >#8 8 0.7079778 0.5465055 0.8951371 >#9 9 0.0564100 0.1837211 0.6451289 >#10 10 0.7169663 0.1328287 0.2467554 > Reduce(function(...) merge(...,by="x"),dfs) ># x a b c >#1 1 0.7113766 0.1348978 0.1153703 >#2 2 0.2520057 0.7249154 0.2362936 >#3 3 0.5670157 0.8166805 0.3049683 >#4 4 0.7441726 0.4929165 0.6779029 >#5 5 0.5616914 0.5272339 0.6202915 >#6 6 0.2858429 0.1203205 0.8399356 >#7 7 0.9910520 0.1251815 0.4729418 >#8 8 0.7079778 0.5465055 0.8951371 >#9 9 0.0564100 0.1837211 0.6451289 >#10 10 0.7169663 0.1328287 0.2467554 >A.K. > > > >________________________________ > From: Janesh Devkota <janesh.devk...@gmail.com> >To: Farnoosh <farnoosh...@yahoo.com> >Cc: arun <smartpink...@yahoo.com>; R help <r-help@r-project.org> >Sent: Wednesday, April 17, 2013 1:05 PM >Subject: Re: [R] Merge > > > > >Hi, I have a quick question here. Lets say he has three data frames and he >needs to combine those three data frame using merge. Can we simply use merge >to join three data frames ? I remember I had some problem using merge for more >than two dataframes. > >Thanks. > > > >On Wed, Apr 17, 2013 at 1:05 AM, Farnoosh <farnoosh...@yahoo.com> wrote: > >Thanks a lot:) >> >>Sent from my iPad >> >> >>On Apr 16, 2013, at 10:15 PM, arun <smartpink...@yahoo.com> wrote: >> >>> Hi Farnoosh, >>> YOu can use either ?merge() or ?join() >>> DataA<- read.table(text=" >>> ID v1 >>> 1 10 >>> 2 1 >>> 3 22 >>> 4 15 >>> 5 3 >>> 6 6 >>> 7 8 >>> ",sep="",header=TRUE) >>> >>> DataB<- read.table(text=" >>> ID v2 >>> 2 yes >>> 5 no >>> 7 yes >>> ",sep="",header=TRUE,stringsAsFactors=FALSE) >>> >>> merge(DataA,DataB,by="ID",all.x=TRUE) >>> # ID v1 v2 >>> #1 1 10 <NA> >>> #2 2 1 yes >>> #3 3 22 <NA> >>> #4 4 15 <NA> >>> #5 5 3 no >>> #6 6 6 <NA> >>> #7 7 8 yes >>> library(plyr) >>> join(DataA,DataB,by="ID",type="left") >>> # ID v1 v2 >>> #1 1 10 <NA> >>> #2 2 1 yes >>> #3 3 22 <NA> >>> #4 4 15 <NA> >>> #5 5 3 no >>> #6 6 6 <NA> >>> #7 7 8 yes >>> A.K. >>> >>> >>> >>> >>> >>> ________________________________ >>> From: farnoosh sheikhi <farnoosh...@yahoo.com> >>> To: "smartpink...@yahoo.com" <smartpink...@yahoo.com> >>> Sent: Wednesday, April 17, 2013 12:52 AM >>> Subject: Merge >>> >>> >>> >>> Hi Arun, >>> >>> I want to merge a data set with another data frame with 2 columns and keep >>> the sample size of the DataA. >>> >>> DataA DataB DataCombine >>> ID v1 ID V2 ID v1 v2 >>> 1 10 2 yes 1 10 NA >>> 2 1 5 no 2 1 yes >>> 3 22 7 yes 3 22 NA >>> 4 15 4 15 NA >>> 5 3 5 3 no >>> 6 6 6 6 NA >>> 7 8 7 8 yes >>> >>> >>> Thanks a lot for your help and time. >> >>______________________________________________ >>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. >> > ______________________________________________ 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.
