[R] Merging data

[Liaw, Andy]

Something like this?

> data1 <- data.frame(id=c(1, 3, 5), x=runif(3))
> data2 <- data.frame(id=1:10, y=runif(10))
> data3 <- merge(data1, data2, by="id", all.x=TRUE, all.y=FALSE)
> data3
  id         x         y
1  1 0.9533341 0.1803271
2  3 0.9143624 0.5033228
3  5 0.2866931 0.4233733

Andy

From: Brian Perron
> 
> Hello all,
> 
> I am fairly new to R and am trying to bring together data 
> from multiple sources.  Here is one problem that I cannot 
> seem to crack - I hope somebody can help.  Let me simplify 
> the problem:  Let's say I have two datasets:  DATA1 and 
> DATA2.  I would like to work with all the cases in DATA2.  I 
> have additional variables on these cases in DATA1, which is a 
> larger data set with many additional cases.  I know how to 
> merge data sets if the datasets contain the same cases.  
> However, I want to eliminate all the cases from DATA1 that 
> are not present in DATA2 and then merge.  The CASEID is my 
> matching variable, and there are no duplicate variable names. 
> Any guidance would be greatly appreciated. 
> 
> Thanks in advance,
> Brian  
> 
> 
> 
> 
> 	[[alternative HTML version deleted]]
> 
>