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

Stata 11 Sample Session Section 2 – Restructuring Data Files – Table Lookup & Aggregation
command to be placed in the do-file. Switch to
the do-file editor and type
levelsof district, local(levels)
3. We can now create variables containing the rank
of the household within each district. We must
type these commands into the do-file because the
command is multiple lines. You are already in the
do-file editor . Type:
foreach z of local levels {
xtile quartile`z’ = cprod_ae if (district == `z’), nq(4)
}
‘z’ is a local macro name which is set to each value in the
variable “levels”. The values we know are 1, 2, and 3. In
the first loop of this programming command z is equal to
1, in the second loop z is equal to 2, etc.
quartile`z’ refers to a variable name where the contents of
z is appended to the name quart, e.g. quart1, quart2,
quart3, etc.
district = `z’, means that for the first loop district is equal
to 1, for the second loop district is equal to 2, etc.
Very important note: The macro name `z’ must be
surrounded by a “left” single quote (found in the upper
left hand corner or the keyboard to the left of the key with
the number 1) and a “right” single quote (found on the
key to the left of the key). If you do not use the
left single quote, you will see an error message that says
in red:
' invalid name
Be sure that you end the first line with a left
curly brace, e.g. { and that you place on a line
by itself after all commands that you want to be
included in the loop, a right curly brace, e.g. }
Since we have 3 districts, 3 new variables will be created
with names of quartile1, quartile2, quartile3.
4. We want all the information in just one variable
so we will create another variable and fill it with
the information from the variables created above.
If you created a variable called “quart” following
the instructions above, you will need to drop it
77