[R] Merge

[arun]

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.devkota at gmail.com>
To: arun <smartpink111 at yahoo.com> 
Cc: R help <r-help at r-project.org>; Farnoosh <farnoosh_81 at 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 <smartpink111 at 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.devkota at gmail.com>
>To: Farnoosh <farnoosh_81 at yahoo.com>
>Cc: arun <smartpink111 at yahoo.com>; R help <r-help at 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_81 at yahoo.com> wrote:
>
>Thanks a lot:)
>>
>>Sent from my iPad
>>
>>
>>On Apr 16, 2013, at 10:15 PM, arun <smartpink111 at 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_81 at yahoo.com>
>>> To: "smartpink111 at yahoo.com" <smartpink111 at 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 at 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.
>>
>