st: Decode categorical variable based on frequency

["Bhoom Suktitipat" <sibsp@mahidol.ac.th>]

Dear List members,

Is there a possible way to automatically code a categorical variable
based on its frequency?

For example,

my variable contains ( a string variable)

. tab rs1010
 rs1010 |      Freq.     Percent        Cum.
------------+-----------------------------------
        1/1 |        353       64.77       64.77
        1/3 |        163       29.91       94.68
        3/3 |         29        5.32      100.00
------------+-----------------------------------
      Total |        545      100.00


If I use decode rs1010, gen(newrs) I got 1/1 as 0 instead.
Basically, I want to encode 3/3 (lowest frequency category) as 0, 1/3
as 1, and 1/1 as 2.

Any hint is appreciated.

Best,
~Bhoom
*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/