I have 2 data frames:
A with 125 rows (=individuals), and 20 vriables
B with 250 rows, and 2 variables
Both have a pid, so we can identify individuals in both frames.
I want a dataframe that contains all individuals from A, but also the 2 variables from B, that A does not content. I do not want to have more rows in A, i.e. individuals from B that are not part of A.
I tried merge, match, aso, and can't get it working. Anybdy here to help me?