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From |
Nick Cox <njcoxstata@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: Mark observations with missing data |

Date |
Fri, 6 Jan 2012 18:51:45 +0000 |

-dropmiss- is mine. The reason there isn't a -markmiss-, as it were, is as Alan explains because Stata's inbuilt function -missing()- exists. With large numbers of variables, egen ismissing = rowmiss(*) is an alternative. The value of -ismissing- is not restricted to 0 or 1, evidently, but ... if ismissing catches observations with missing values regardless. But it is only numeric variables you are concerned about regress <varlist> gen ismissing = !e(sample) is a statistical way of doing this. Nick On Fri, Jan 6, 2012 at 6:16 PM, Richard Herron <richard.c.herron@gmail.com> wrote: > Thanks, Alan! I knew that I had to missing something (here largely > failing to read the manual :) ). > > I guess I can really do this in one line -generate byte missing = > missing(mpg, price, rep78)-. On Fri, Jan 6, 2012 at 13:07, Alan Neustadtl <alan.neustadtl@gmail.com> wrote: >> The missing function might be useful here. See -help missing()-. For example: >> >> /* Begin example */ >> >> sysuse auto, clear >> gen missvar=0 >> replace missvar=1 if missing(rep78, mpg, price) >> list rep78 mpg price missvar >> >> /* End example */ On Fri, Jan 6, 2012 at 1:00 PM, Richard Herron >>> I learned about -dropmiss- (Stata Journal) from this Stata List post: >>> http://www.stata.com/statalist/archive/2010-05/msg00513.html >>> >>> But I would like to keep all observations and just mark the ones with >>> missing observations in a given -varlist-. This way with an -if- >>> statement I can find summary statistics for the same data that I will >>> later use in regressions. I provide a hackish solution below, but is >>> there a better way? Is there anything flawed with my approach? I am a >>> little wary of loops and my own coding. Thanks! >>> >>> Here is my hackish solution if I want to mark observations with any >>> missing variables. >>> >>> * begin code >>> sysuse auto, clear >>> replace price = . in 1 >>> replace mpg = . in 2 >>> list in 1/5 >>> >>> * hackish solution >>> generate byte complete = 1 >>> foreach x of varlist * { >>> replace complete = 0 if missing(`x') >>> } >>> list in 1/5 >>> * end code * * 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/

**References**:**st: Mark observations with missing data***From:*Richard Herron <richard.c.herron@gmail.com>

**Re: st: Mark observations with missing data***From:*Alan Neustadtl <alan.neustadtl@gmail.com>

**Re: st: Mark observations with missing data***From:*Richard Herron <richard.c.herron@gmail.com>

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