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| From | Michael McCulloch <mm@pinestreetfoundation.org> |
| To | statalist@hsphsun2.harvard.edu |
| Subject | Re: st: RE: AW: RE: AW: recode 9, 99, 999,..., into missing |
| Date | Mon, 17 May 2010 10:38:39 -0700 |
Thanks for the explanation! On May 17, 2010, at 10:29 AM, Martin Weiss wrote:
<> Just to be sure, we are talking about the "programming if" here -helpifcmd-, not the qualifier, the source of much confusion in the past on thelist.-su, mean- leaves behind a scalar value for the maximum, and the ifs check on its range. So there is only one "correct" answer per loop iteration to the if/else, and this one is executed. For the -if- qualifier, nothing much would change, as discussed earlier, only the code would be executed morefrequently, i.e. _N times. HTH Martin -----Original Message----- From: owner-statalist@hsphsun2.harvard.edu[mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Michael McCullochSent: Montag, 17. Mai 2010 19:14 To: statalist@hsphsun2.harvard.edu Subject: Re: st: RE: AW: RE: AW: recode 9, 99, 999,..., into missing 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 valuessuch 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!* * 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/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 * * 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/ * * 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/
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 * * 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/