[R] merging 2 frames while keeping all the entries from the "reference" frame

[Henrique Dallazuanna]

Try this:

 merge(mydata, cbind(reference, group = rep(unique(mydata$group), each
= nrow(reference))), all = TRUE)

On Mon, Apr 4, 2011 at 2:24 PM, Dimitri Liakhovitski
<dimitri.liakhovitski at gmail.com> wrote:
> To clarify just in case, here is the result I am trying to get:
>
> mydate  group   values
> 12/29/2008      Group1  0.453466522
> 1/5/2009        Group1  NA
> 1/12/2009       Group1  0.416548943
> 1/19/2009       Group1  2.066275155
> 1/26/2009       Group1  2.037729638
> 2/2/2009        Group1  -0.598040483
> 2/9/2009        Group1  1.658999227
> 2/16/2009       Group1  -0.869325211
> 12/29/2008      Group2  NA
> 1/5/2009        Group2  NA
> 1/12/2009       Group2  NA
> 1/19/2009       Group2  0.375284194
> 1/26/2009       Group2  0.706785401
> 2/2/2009        Group2  NA
> 2/9/2009        Group2  2.104937151
> 2/16/2009       Group2  2.880393978
>
>
>
> On Mon, Apr 4, 2011 at 1:09 PM, Dimitri Liakhovitski
> <dimitri.liakhovitski at gmail.com> wrote:
>> Hello!
>> I have my data frame "mydata" (below) and data frame "reference" -
>> that contains all the dates I would like to be present in the final
>> data frame.
>> I am trying to merge them so that the the result data frame contains
>> all 8 dates in both subgroups (i.e., Group1 should have 8 rows and
>> Group2 too). But when I merge it it's not coming out this way. Any
>> hint would be greatly appreciated!
>> Dimitri
>>
>> mydata<-data.frame(mydate=rep(seq(as.Date("2008-12-29"), length = 8,
>> by = "week"),2),
>> group=c(rep("Group1",8),rep("Group2",8)),values=rnorm(16,1,1))
>> (reference);(mydata)
>> set.seed(1234)
>> out<-sample(1:16,5,replace=F)
>> mydata<-mydata[-out,]; dim(mydata)
>> (mydata)
>>
>> # "reference" contains the dates I want to be present in the final data frame:
>> reference<-data.frame(mydate=seq(as.Date("2008-12-29"), length = 8, by
>> = "week"))
>>
>> # Merging:
>> new.data<-merge(mydata,reference,by="mydate",all.x=T,all.y=T)
>> new.data<-new.data[order(new.data$group,new.data$mydate),]
>> (new.data)
>> # my new.data contains only 7 rows in Group 1 and 4 rows in Group 2
>>
>>
>> --
>> Dimitri Liakhovitski
>> Ninah Consulting
>>
>
>
>
> --
> Dimitri Liakhovitski
> Ninah Consulting
> www.ninah.com
>
> ______________________________________________
> 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.
>



-- 
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O