How to merge two columns in R with a specific symbol?
I have a table read in R as follows:
column1 column2
A B
What is the command to be used to match two columns together as follows?
Column 3
A_B
Answer
I'm a bit unsure what you mean by "merge", but is this what you mean?
> DF = data.frame(A = LETTERS[1:10], B = LETTERS[11:20])
> DF$C = paste(DF$A, DF$B, sep="_")
> head(DF)
A B C
1 A K A_K
2 B L B_L
3 C M C_M
4 D N D_N
Or equivalently, as @daroczig points out:
within(DF, C <- paste(A, B, sep='_'))