Multiple merge, better solution?
Hi: Below is a TOTAL HACK and I don't recommend it but it does seem to
do what you want. I think that I remember Gabor saying that you can
merge multiple data frames using zoo but I don't know the specifics. I'm
sure he'll respond with the correct way. Below uses a global variable
to access the
dataframe inside the loop and keeps adding on to it. Don't use it unless
you're really desperate for a solution.
DF <- DF1
for ( .df in list(DF2,DF3,DF4) ) {
DF<<-merge(DF,.df,by.x="var1", by.y="var1", all=T)
}
print(DF)
On Thu, Feb 19, 2009 at 5:21 AM, Lauri Nikkinen wrote:
Hello, My problem is that I would like to merge multiple files with a common column but merge accepts only two data.frames to merge. In the real situation, I have 26 different data.frames with a common column. I can of course use merge many times (see below) but what would be more sophisticated solution? For loop? Any ideas? DF1 <- data.frame(var1 = letters[1:5], a = rnorm(5)) DF2 <- data.frame(var1 = letters[3:7], b = rnorm(5)) DF3 <- data.frame(var1 = letters[6:10], c = rnorm(5)) DF4 <- data.frame(var1 = letters[8:12], d = rnorm(5)) g <- merge(DF1, DF2, by.x="var1", by.y="var1", all=T) g <- merge(g, DF3, by.x="var1", by.y="var1", all=T) merge(g, DF4, by.x="var1", by.y="var1", all=T) Thanks in advance. -Lauri
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