st: Re: First non-zero observation within a variable

["Michael Blasnik" <michael.blasnik@verizon.net>]

...
I just have to chime in on this one since I haven't seen anyone mention a 
simple one line solution:

bysort group (time): drop if sum(expression!=0 & expression<.)==0

Michael Blasnik

----- Original Message ----- 
From: "Thomas Speidel" <thomas@tmbx.com>
To: <statalist@hsphsun2.harvard.edu>
Sent: Sunday, February 04, 2007 12:38 AM
Subject: st: First non-zero observation within a variable



> I am trying to tag the first non-zero, non-missing observation within a
> variable by group.  The goal is to drop anything BEFORE the expression
> is measured within a group.  For example:
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