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From |
"Nick Cox" <n.j.cox@durham.ac.uk> |

To |
<statalist@hsphsun2.harvard.edu> |

Subject |
st: RE: Testing for a contiguous subset of observations? |

Date |
Fri, 30 Nov 2007 11:58:43 -0000 |

Some people call such problems "spell" problems. Others might talk of runs. Either way, discussions and tools exist. -tsspell- from SSC and the discussion in SJ-7-2 dm0029 . . . . . . . . . . . . . . Speaking Stata: Identifying spells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . N. J. Cox Q2/07 SJ 7(2):249--265 (no commands) shows how to handle spells with complete control over spell specification apply. See the help file for -tsspell- which includes several examples. Nick n.j.cox@durham.ac.uk BW Wheeler I'm having trouble figuring out a solution to this data management problem, and have exhausted all books and findit (partly as it's hard to know what to search for)! I have time series data captured from accelerometers, with an observation of 'activity counts' logged every 10 seconds for several days for each individual. If the number of counts is zero continuously for any period of 10 minutes or more (i.e. 60+ observations), we need to assume that the accelerometer was not being worn, and to treat these zeros as missing. So, my data look something like this: Observation Date Time Activity 1 13/05/2006 15:20:00 230 2 13/05/2006 15:20:10 215 3 13/05/2006 15:20:20 0 4 13/05/2006 15:20:30 0 5 13/05/2006 15:20:40 0 ... Does anyone have any ideas of how I can replace the 'Activity' value with missing, if that value is a zero in the midst of a continuous series of 60+ zeros? * * For searches and help try: * http://www.stata.com/support/faqs/res/findit.html * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

**References**:**st: Testing for a contiguous subset of observations?***From:*BW Wheeler <ben.wheeler@bristol.ac.uk>

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