Members might like to compare -vreverse-, on SSC since 2003.
Kyle's program can cope with several variables at once. -vreverse-
can't, but you could just use a loop to cycle over variables:
foreach v of var <varlist> {
vreverse `v', gen(rev`v')
}
Contrariness, -vreverse- has some other bells and whistles
and is self-contained.
Nick
[email protected]
Kyle C Longest
Thanks to Kit Baum, a new program, -revrs-, is available on SSC.
. ssc install revrs
-revrs- is a module to reverse the order of a variable's values and
maintain specified value labels. –revrs- is especially helpful for
quickly recoding multiple categorical or ordinal response variables to
follow a similar direction.
Version 8.2 of Stata required.
The primary purpose of the program is to allow users to reverse order
variables in one step, and keep the value labels. This is helpful in
cases when surveys will ask similar questions but switch the direction
of the response categories (e.g., is “Never” coded as 0 or as 5).
Granted most Stata programs will inherently control for this reverse
ordering, but this program can be helpful for aesthetic (e.g.,
frequency distributions, cross tabs) purposes (especially if the user
is directly copying tables out of Stata) and to reduce possible
confusion (e.g., interpreting negative coefficients).
Example:
. tab drink
drink | Freq. Percent Cum.
-------------------+-----------------------------------
Every_Day | 99 9.90 9.90
Almost_Every_Day | 101 10.10 20.00
Once a Week | 40 4.00 24.00
Once A month | 159 15.90 39.90
A few times a Year | 301 30.10 70.00
Never | 300 30.00 100.00
-------------------+-----------------------------------
Total | 1,000 100.00
. revrs drink
. tab revdrink
revdrink | Freq. Percent Cum.
-------------------+-----------------------------------
Never | 300 30.00 30.00
A few times a Year | 301 30.10 60.10
Once A month | 159 15.90 76.00
Once a Week | 40 4.00 80.00
Almost_Every_Day | 101 10.10 90.10
Every_Day | 99 9.90 100.00
-------------------+-----------------------------------
Total | 1,000 100.00
-revrs- accepts a variable list, and without any options will create a
new variable with “rev” appended to the front of the original
variable(s) name. The –REPLace- option automatically overwrites the
original variable (keeping its name) with the reversed version.
Finally, it must be noted that –revrs- does not deal with the values
themselves, only their order. So if the actual values are of
importance, an extra step would be needed.
The program utilizes Roger Newsom’s –sencode- which will be installed
(if not already) alongside –revrs- when done from inside Stata.
Hopefully it will be as helpful in saving time and headaches for others
as it has for me, and suggestions and comments are, as usual, more than
welcomed.
*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
