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Re: st: global keys


From   Michael McCulloch <mm@pinest.org>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: global keys
Date   Fri, 14 Sep 2007 08:04:50 -0700

Thank you Svend!

Michael McCulloch wrote:

I have a dataset which contains a variable <site_02>
containing a long list of tumor ID codes, from which
I want to keep ten: C180 through C189.

Is there a less labor-intensive way to do the following:

keep if site_02=="C180" | site_02=="C181" | site_02=="C182" | ///
site_02=="C183" | site_02=="C184" | site_02=="C185" | ///
site_02=="C186" | site_02=="C187" | site_02=="C188" | site_02=="C189"

----------------------------------------------------------

Yes!  You can:

   keep if site_02 >= "C180" & site_02 < "C190"

Relational operators also work with strings:

" " < "12" < "2" < "A" < "AA" < "Z" < "a"

Strings are sorted in dictionary sequence; however, all uppercase
letters come before lowercase, numbers come before letters, and
spaces or blanks come before anythng else.

Hope this helps.
Svend
________________________________________________________

Svend Juul
Institut for Folkesundhed, Afdeling for Epidemiologi
(Institute of Public Health, Department of Epidemiology)
Vennelyst Boulevard 6
DK-8000 Aarhus C,  Denmark
Phone, work:  +45 8942 6090
Phone, home:  +45 8693 7796
Fax:          +45 8613 1580
E-mail:       sj@soci.au.dk
_________________________________________________________

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