Merging more than 2 dataframes in R by rownames

Question

I gather data from 4 df\'s and would like to merge them by rownames. I am looking for an efficient way to do this. This is a simplified version of the data I have.

Answer 1

Three lines of code will give you the exact same result:

dat2 <- cbind(df1, df2, df3, df4)
colnames(dat2)[-(1:7)] <- paste(paste('V', rep(1:100, 2),sep = ''),
                            rep(c('x', 'y'), each = 100), sep = c('.'))
all.equal(dat,dat2)    

Ah I see, now I understand why you are getting into so much pain. Using the old for loop surely does the trick. Maybe there are even more clever solutions

rn <- rownames(df1)
l <- list(df1, df2, df3, df4)
dat <- l[[1]]
for(i in 2:length(l)) {
  dat <- merge(dat, l[[i]],  by= "row.names", all.x= F, all.y= F) [,-1]
  rownames(dat) <- rn
}