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st: -egenmore- revised on SSC
Thanks to Kit Baum, the -egenmore- package has been revised
on SSC. Interested users of Stata 7 up should please install,
or re-install, using -ssc. (The minimum requirements of the
functions in -egenmore- vary from Stata 6 to later, but
Stata 6 users should not update, as explained below.)
-egenmore- is a set of -egen- functions written by
Nick Winter, Steven Stillman, Ulrich Kohler, Kit Baum
(Please note also that many other people outside StataCorp
-- and a few inside -- have written -egen- functions that
are not part of official Stata, as -findit egen- will bear
Individual -egen- functions are not that big a deal, but an -egen-
habit encourages some small civic virtues:
* -egen- functions generate a single variable, typically
following a simple recipe. Maintaining separate packages
for such commands would add to the complications faced by
users, including the package authors.
* -egen- encourages more uniform syntax.
* Having a library of functions makes it more likely
that other user-programmers can solve a nearby problem
by modifying an existing program.
On the other hand, be aware that
* Using -egen- in a program can be very inefficient,
especially if there are repeated calls to a particular
function. In essence you oblige Stata to interpret several
dozen lines of code each time and, done repeatedly,
that might not be trivial.
* Just because there's an -egen- function to do something
doesn't mean -egen- is the best way to do that, even once.
Sometimes looking up the -egen- syntax and working out
what it should be in your case takes more time than a
Generalities aside, the following changes in -egenmore- seem
1. The help is much revised. It has been rewritten in
SMCL. This disenfranchises any Statalist members on
version 6 or earlier. However, any members on Stata 5
or earlier will find no functions in this package that
will work with their Stata. I trust that any members
on Stata 6 interested in -egenmore- have long since
installed a copy. They should not update, as there
is nothing new they can use.
In the revised help, functions have been grouped
thematically, definitions and examples have been integrated,
and many comments added. As -egenmore- has an archive function,
we don't drop stuff that appears obsolete or superseded given
current Stata, but we try to flag alternatives.
For example, in his very recent book Svend Juul kindly
refers to -egenmore-, including references to functions
arguably already superseded by other commands. Readers of Svend's
book are going to expect that stuff to be there because
he quotes it.
2. Ulrich Kohler's -mlabvpos()- function for positioning
marker labels joins the package.
The separate package -gmlabvpos- is no more.
3. There are other new functions:
-adjl()-, -adju()- and -outside()- compute the
adjacent values and outside values shown on boxplots.
If you want to emulate some or all the features of
boxplots you may need these in addition to the usual
functions yielding extremes, quartiles and medians.
-dayofyear()- and -foy()- compute number of days
and fraction of year elapsed since the start of the year
from daily date variables. The start can be set to any
date other than 1 January.
-total0()- is a variant on official Stata's -egen, total()-.
A total is shown if and only if all values are non-missing;
otherwise missing is shown.
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