Re: st: RE: AW: RE: AW: recode 9, 99, 999,..., into missing

[Michael McCulloch <mm@pinestreetfoundation.org>]

Thanks Nick, this helped me understand the code. Am I correct then to  
understand that:
. if r(max)<=9 mvdecode `var', mv(9)
 	means: "change all values of 9 to missing when 9 is the max of the  
range"

. else if inrange(r(max),10,99) mvdecode `var', mv(99)
	means: "change all values of 99 to missing when the range is 10 to 99"

. else if inrange(r(max),100,999) mvdecode `var', mv(999)
	means: "change all values of 999 to missing when the range is 100 to  
999"

. else mvdecode `var', mv(9999)
	means: "change all values of 9999 to missing"

Michael


On May 17, 2010, at 9:58 AM, Nick Cox wrote:

> 99 isn't changed because there are bigger values in the same  
> variable. Thus, it is assumed that it does not mean missing.
>
> Nick
> n.j.cox@durham.ac.uk
>
>
> -----Original Message-----
> From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu 
> ] On Behalf Of Michael McCulloch
>
>
> In Martin's code, I noticed that:
> 	for observation #8, var4 is changed to missing,
> 	for observation #4, var3 is not changed to missing.
> This puzzled me because they both have "999" as original value.
>
> It also looks like values "9", "999" and "9999" are changed to
> missing, but not "99".
> Michael
>
> On May 17, 2010, at 9:30 AM, Lachenbruch, Peter wrote:
>
> > Looks good to me.
> >
> > Tony
> >
> > Peter A. Lachenbruch
> > Department of Public Health
> > Oregon State University
> > Corvallis, OR 97330
> > Phone: 541-737-3832
> > FAX: 541-737-4001
> >
> > -----Original Message-----
> > From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu
> > ] On Behalf Of Martin Weiss
> > Sent: Monday, May 17, 2010 12:35 AM
> > To: statalist@hsphsun2.harvard.edu
> > Subject: AW: st: RE: AW: RE: AW: recode 9, 99, 999,..., into missing
> >
> >
> > <>
> >
> > What does the -mvdecode- solution look like then? Like this?
> >
> >
> >
> > *************
> > clear*
> >
> > inp byte(var1 var2) int(var3 var4)
> > 1 1 1 1
> > 2 2 2 2
> > 3 3 3 3
> > 4 8 99 999
> > 5 9 100 1000
> > 6 10 101 1001
> > 7 11 150 5000
> > 9 12 999 9999
> > end
> >
> > foreach var of varlist *{
> > 	sum `var', mean
> > 	if r(max)<=9 mvdecode `var', mv(9)
> > 	else if inrange(r(max),10,99) mvdecode `var', mv(99)
> > 	else if inrange(r(max),100,999) mvdecode `var', mv(999)
> > 	else mvdecode `var', mv(9999)
> > }
> >
> > li, noo
> > *************
> >
> >
> >
> > HTH
> > Martin
> >
> >
> > -----Ursprüngliche Nachricht-----
> > Von: owner-statalist@hsphsun2.harvard.edu
> > [mailto:owner-statalist@hsphsun2.harvard.edu] Im Auftrag von Steve
> > Samuels
> > Gesendet: Montag, 17. Mai 2010 03:00
> > An: statalist@hsphsun2.harvard.edu
> > Betreff: Re: st: RE: AW: RE: AW: recode 9, 99, 999,..., into missing
> >
> > Mandy, if you know this much about each variable, I see no advantaqe
> > or necessity to your approach.  -mvdecode- appears to be superior in
> > every way.  It is not only more direct,  clearer, and  will  handle
> > all the other "non-data" codes. Clarity is very important: other
> > people (and you, perhaps, in the future) will be able to understand
> > your Stata statements without any lengthy explanation.  None of the
> > other solutions can claim that.
> >
> > Steve
> >
> >
> >
> > On Sun, May 16, 2010 at 8:33 PM, Amanda Fu <mandy.fu1@gmail.com>
> > wrote:
> > > Dear Mr. Weiss and Lachenbruch,
> > >
> > > I am sorry that I should be more clear when describing my question.
> > > In
> > > my opinion, I need to be careful about this problem : for example,
> > > for
> > > a variable  that has 10 scales, the 9 value means a real scale and  
> > > 99
> > > in that case means "not answered".
> > >
> > > The pattern is like this:
> > > (1) if the maximum value  of a variable is smaller than 9 , then the
> > > "not answered" takes the value 9;
> > > (2) if the maximum value  of a variable is smaller than 99 but
> > > greater
> > > than 10, then the "not answered"   takes the value 99;
> > > (3) if the maximum value  of a variable is smaller than 999 but
> > > greater than 100, then the "not answered"  takes the value 999;
> > > and so on.
> > >
> > > (And you are absolutely right for the reminder that there are values
> > > such as 7,8, 98, or 97 to indicate "refused to answer" "invalid
> > > answer". Here I would like to keep focus on one example of "not
> > > answered" , because the other values could be dealt with using the
> > > same way.)
> > >
> > > Thanks for help from both of you!
>
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Best wishes,

Michael McCulloch, LAc MPH PhD
Pine Street Foundation
124 Pine Street
San Anselmo, CA 94960-2674
tel:	415-407-1357
fax: 	206-338-2391


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