st: Egen ends behavior apparently violates rules in documentation

[Devra Golbe <Devra.Golbe@hunter.cuny.edu>]

Hi,

 the following code fragment suggests that egen ends does not operate as 
the documentation  (pasted at the bottom of my message) 
suggests.  Specifically,  with the tail option, if no punct(pchars) 
appears, the tail should be empty. However, my output suggests that under 
these circumstances (no appearance of pchars) the tail contains the entire 
"word".

Thanks in advance for your insights.

Devra

*******
. which egen
C:\STATA7\ado\updates\e\egen.ado
*! version 3.3.2  07may2001


. egen consid1=ends(consid), punct(*) head;

. egen considt=ends(consid), punct(*) tail;

. egen consid2=ends(considt), punct(*) head;

. egen considt2=ends(considt), punct(*) tail;

. list consid  consid1 consid2 considt2 in 1/10;

                             consid    consid1    consid2             considt2
  1.                  CASH*NOTE*LIA       CASH       NOTE                  LIA
  2.                           CASH       CASH       CASH                 CASH
  3.                           CASH       CASH       CASH                 CASH

*******



ends(strvar) [, punct(pchars) trim [head|tail|last]]
    may not be combined with by.  It gives the first "word" or head (with 
the head option), last
    "word" (with the last option), or the remainder or tail (with the tail 
option) from string
    variable strvar.

    head, last and tail are determined by the occurrence of pchars, which 
is by default a single
    space " ".

    [snip]

    The remainder or tail is whatever follows the first occurrence of 
pchars, which will be the empty
    string "" if it does not occur.  The tail of "frog toad newt" is "toad 
newt" and of "frog" is "".
    With punct(,), the tail of "frog,toad" is "toad".



_____________________________________________
Devra L. Golbe , Professor
Department of Economics
Hunter College
695 Park Ave., NY, NY 10021
voice: 212-772-5408
fax:    212-772-5398
e-fax: 208-361-5964

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