Merge three datasets with different sizes, column names-CodePudding

So basically I'm trying to merge three quite different datasets – three to be precise. I have tried using the merge() function but without any success since the different samples vary, as well as column names.

Any suggestions how to tackle my problem?

CodePudding user response：

what you seek for is the JOIN operation; but you need to specify columns to merge on in order to resolve ambiguities

require(data.table)
dt1 = data.table(col1=1:10, col2=5:14)
dt2 = data.table(col1=11:20, col22=LETTERS[1:10])
dt3 = data.table(col2=5:14, col3=101:110)
as.data.frame(merge(merge(dt1,dt2, all=TRUE), dt3, by='col2'))