In R, I have two data frames A & B as follows-
Data-Frame A:
Name Age City Gender Income Company ...
JXX 21 Chicago M 20K XYZ ...
CXX 25 NewYork M 30K PQR ...
CXX 26 Chicago M NA ZZZ ...
Data-Frame B:
Age City Gender Avg Income Avg Height Avg Weight ...
21 Chicago M 30K ... ... ...
25 NewYork M 40K ... ... ...
26 Chicago M 50K ... ... ...
I want to fill missing values in data frame A from data frame B.
For example, for third row in data frame A I can substitute avg income from data frame B instead of exact income. I don't want to merge these two data frames, instead want to perform look-up like operation.