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From |
brendan.halpin@ul.ie (Brendan Halpin) |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: sequence analysis |

Date |
Thu, 05 Jan 2012 11:13:23 +0000 |

On Thu, Jan 05 2012, Melanie Spallek wrote: > Hi, I'm trying to do a sequence analysis using housing trajectories > (tenure status). I'm using sqset tenure id wave, trim to define my > sequences. Followed by seqtab, so, I receive a frequency table of the > sequences, however the so option treats identically all sequences that > have the same order of elements; i.e., the sequence A-B-B-A would be > treated the same as A-B-A-A, which is exactly what I want. My first (and > most important) question is if and how I can save those sequences in a > variable. Since my dataset is in long format, I'm aware that by having > ten waves for each id, the 'sequence variable' will be occurring ten > times, which is ok. I would recommend using a string representation of the sequence, in conjunction with Stata's regular expression functions. I have a set of sequence analysis utilities that are complementary to SQ, that include a command to make strings from sequences. It is available thus: . net from http://teaching.sociology.ul.ie/sadi . net install sadi (depends on moremata, in turn available from SSC). This includes a command -stripe- which creates a string representation of the sequence. It works with wide format, so a reshape is needed: . reshape wide tenure, i(id) j(wave) . stripe tenure1-tenure10, gen(seqstr) . tab seqstr if regexm(seqstr, "^A+B+A+$") Regular expresssions are a little complicated but are a very good way of specifying sequence patterns. This example goes from the start of the sequence ("^") to the end ("$") and specifies that the sequence consists of one or more As followed by one or more Bs followed by one or more As. "+" means one or more, "*" means zero or more, "." matches anything. Brendan -- Brendan Halpin, Department of Sociology, University of Limerick, Ireland Tel: w +353-61-213147 f +353-61-202569 h +353-61-338562; Room F1-009 x 3147 mailto:brendan.halpin@ul.ie ULSociology on Facebook: http://on.fb.me/fjIK9t http://teaching.sociology.ul.ie/bhalpin/wordpress twitter:@ULSociology * * 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: How to solve "repeated time values" error message for panel dataset***From:*Nataliya Acc <p99asn01@yahoo.com>

**Re: st: How to solve "repeated time values" error message for panel dataset***From:*Maarten Buis <maartenlbuis@gmail.com>

**st: sequence analysis***From:*Melanie Spallek <m.spallek@uq.edu.au>

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