.-
 help for ^enlarge^                         Stas Kolenikov, skolenik@@yahoo.com
.-


 Extending a value across a group of observations
 ------------------------------------------------

        ^enlarge^ variable, ^by(^grouping variables^)^


 Description
 -----------

^enlarge^ is used to spread a value of the variable across all observations
in the specified groups, if this value occurs only once in these groups.

I.e., the data are transformed as follows:

(sorted by: group)

 value     group                         value     group
   .         1                             5         1
   5         1                             5         1
   .         1                             5         1
   .         1                             5         1
   .         2              =>             3         2
   .         2                             3         2
   3         2                             3         2
   .         3                             .         3
   2         4                             2         4
   .         4                             2         4

During the transformation, ^enlarge^ would issue a warning stating that
"there are groups with no observations on value". It does not tolerate
several observations within a group, however (though it does not check
whether they coincide, either).

Extensions to string variable and multiple non-missing observations can
be done upon request. I am not interested at the moment :).


 Options
 -------

^by^ specifies the identifiers of the group to extend the value to.
        This is a required option!


 Examples
 --------

Suppose we have a panel data set on several countries, but area is reported
only once for each country.

 . ^enlarge area, by(country)^

We suppose that area of the country does not change during the period of
observation. I.e. the data set should not go back to the 18th century :).


 Author
 ------

Stas Kolenikov, skolenik@@[ recep.glasnet.ru | nes.cemi.rssi.ru | yahoo.com ]
