Renaming parts of the variable name

[Wiebke Stein]

Hi,
I have two data sets, that I want to append. They contain the same variables and information. However, the variables are named differently in both data sets. In data set A variables are named: v31002, v31003, v31004..... In data set B variables are named: v31202, v31203, v31204....
I now want to rename the variables from data set B, so that they are the same as in data set A. Hence, I want to replace the 2 (or: the 4th digit of each variable name) with a 0. So my question only refers to the name of the variable, not the content.
Is there a possiblity to do this with a loop? So that I don´t have to rename every variable individually?

Many thanks and best,
Wiebke

[Nick Cox]

1. Look at the help.

help rename groups

2. Experiment.

clear 
set obs 1
foreach v in v31002 v31003 v31004 { 
    gen `v' = 42
}

ds 

rename (v310*) (v312*) 

ds

v31202  v31203  v31204

[daniel klein]

Something like

rename ( v31(#)(##) )( v310.(##) )

should work.

Nick's code in #2 is simpler; might be less safe if there are variables matching v31* that you do not want to rename.

Best
Daniel

[Wiebke Stein]

Thanks a lot!! It worked