STATA 11 for Windows SAMPLE SESSION - Food Security Group ...

Stata 11 Sample Session Section 2 – Restructuring Data Files – Table Lookup & Aggregation
we want to merge by have the same names. We will
rename p1a to unit.
1. From the Data menu select Data utilities then
Rename variable
The rename - Rename variables dialog box will
come up.
2. In the Existing Variables box select p1a. In
the New variable name box type unit.
3. Click on the copy button, switch to the do-file
editor, paste the command, switch back to the
dialog box and click on Ok.
The Stata command is:
rename p1a unit
The joinby command The files are now ready to be merged. We are doing a
“File - Table” merge where the second file is our
“Lookup Table”. We want to keep all records in the
“master” file (or the file in memory) and keep only those
records in the “using” file that match.
1. From the Data menu select Combine datasets,
then select Form all pairwise combinations
within groups
The joinby - form all pairwise combinations within
groups dialog box will open.
2. To fill in the box labeled Filename of dataset
on disk: click on the Browse button, Select the
filename conver.dta and click on Open.
3. In the box labeled Join observations by
groups formed from specific variables, select
prod unit
4. Click on the “Options” tab.
5. Under “Unmatched Observations”, select
Include from data in memory
This option will keep cases in the “master”
data set (in memory) that do not have a match
in the lookup data set.
6. Click on the copy button, switch to the do-file
editor, paste the command, delete the directory
reference, switch back to the dialog box and
click on Ok
The Stata command is
joinby prod unit using "conver.dta",
unmatched(master) _merge(_merge)
The above command tells Stata to merge the working
data file or “master” (the file in memory) with the
58