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

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: capturing the sizes of the sequences of countinous (uninterrupted) values equal to 1 |

Date |
Wed, 30 Nov 2011 09:36:31 +0000 |

You can't get this information given your data structure into a single Stata variable. What you seek is a matrix. If w <= 244, you could try concatenating your variables into a string variable holding individuals' history. But I guess this would be easier after -reshape long-. Then a spell is defined as a sequence with all 1s for the same id. See then 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 tsspell from http://fmwww.bc.edu/RePEc/bocode/t 'TSSPELL': module for identification of spells or runs in time series / tsspell examines the data, which must be tsset time series, to / identify spells or runs, which are contiguous sequences defined / by some condition. tsspell generates new variables indicating / distinct spells, Nick On Wed, Nov 30, 2011 at 9:24 AM, massimiliano stacchini <mastacchini@yahoo.it> wrote: > I have a huge dataset. The rows identify the person ID (i) (i=1,...,n) while in columns there are the reference dates TIME(t) (t=1,...,w). Each cells contain the value 1 or 0 (zero), alternatively. > > I should create a variable (LENGTH) varying both over ID and TIME. > For each i of ID(i) in t of TIME(t), LENGTH should captures the number of continuous (uninterrupted) values which are equal to 1 in the interval of cells starting from the reference data t of TIME and moving backwards to the previous reference dates. > In other terms , LENGTH should capture for each (i) of ID and for each (t) of TIME the number of s in T (t-s) identifying cells having values equal to 1 (i.e., the size of the sequence of uninterrupted 1 moving backwards to the previous reference dates). > * * 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/

**Follow-Ups**:**Re: st: capturing the sizes of the sequences of countinous (uninterrupted) values equal to 1***From:*Nick Cox <njcoxstata@gmail.com>

**References**:**st: capturing the sizes of the sequences of countinous (uninterrupted) values equal to 1***From:*massimiliano stacchini <mastacchini@yahoo.it>

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