Statalist


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

st: RE: Re: Extended missing values from -destring-


From   "Nick Cox" <n.j.cox@durham.ac.uk>
To   <statalist@hsphsun2.harvard.edu>
Subject   st: RE: Re: Extended missing values from -destring-
Date   Mon, 22 Jun 2009 17:17:04 +0100

In addition to Joseph's positive suggestion, note that the help for
-destring- is quite explicit: 

"destring treats both empty strings "" and "." as indicating sysmiss (.)
and interprets the strings ".a", ".b", ..., ".z" as the extended missing
values .a, .b, ..., .z" 

Thus: 

1. Using -destring- is quite consistent with a user's desire to have
extended missing values. 

2. But as Joseph exemplifies you need to arrange any conversions outside
of -destring-. Any alternative accommodation of extended missing values
within -destring- would just complicate the syntax of -destring- to no
obvious net gain. 

Nick 
n.j.cox@durham.ac.uk 

Joseph Coveney

I'm not sure about a single line of code (unless someone has already
written a
convenience module to do it), but you could do something like

replace var = "." + lower(substr(var, 1, 1)) ///
    if inrange(lower(substr(var, 1, 1,)), "a", "z")

and then -destring- the result.

Bert Jung wrote:

I have a string variable that contains mostly numbers but also
informative missing values like "dk" and "na".  I would like to
-destring- but retain the
cause for the missing values, i.e. produce extended missing values
such as .d and .n where appropriate.  -destring- apparently only
accommodates the system missing value ".".

I could write a few lines (e.g. copy into a second variable and then
replace) but wondered if there is a one-line way to coax -destring-
into producing these extended missing values?


*
*   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/



© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index