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

Stata 11 Sample Session Section 2 – Restructuring Data Files – Table Lookup & Aggregation
Step 1: Generate a household
level file containing the
number of calories produced
per household.
In executing this step, we must keep three things firmly in
mind.
First, all production is currently measured in nonstandard
units. Each unit can have a different weight for
each of the products. Thus, we must first convert all
production into kilograms.
Second, we want to know many calories are produced by
each household, not kilograms. Thus, after converting all
production to kilograms, we must convert kilograms to
calories.
Third, an examination of the file shows that we have data
for each product produced by the household. But we
want to know the total calories produced by the
household for specific food products, not the total
calories from each separate product. After we convert all
production to calories, we must sum the calories within
each household to arrive at the household total.
Let's begin by creating a new do-file. Open the Do-File
Editor. Start by including comments about the purpose
of the do-file, your name as the creator of the do-file and
the date. Other items to include are the Stata version, the
set memory command if you have not changed the startup
memory, the “cd” command to switch to the directory
where you want to work, the log command to record the
session. Example:
version 11
set memory 30m
cd "C:\Documents and Settings\aec_user\My Documents\data"
log using log_session2, append
We are now ready to open c-q4.dta, the production file.
1. Select File / Open...
2. Select the file name c-q4.dta
3. Click on Open to run the command.
4. Copy the command to open this file from the
Results window, switch to the Do-File Editor
( or click on the button on the task bar)
and paste the command into the do-file. Delete
the reference to the directory.
5. Save the do-file to the name session2.do
We must convert all production of the crops into
kilograms. To find the conversion factor appropriate for
56