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From |
"Rodini, Mark" <mrodini@compasslexecon.com> |

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

Subject |
st: using the first n observations in a dataset w/o evaluating the whole thing? |

Date |
Thu, 3 Apr 2008 16:31:58 -0700 |

Greetings. Suppose I have a large Stata dataset (e.g. 3,000,000 observations) and I only with to read in the first, say, 100 observations. I have tried the code, which works: use mydata if ( _N<100 ) However, evidently, this code goes through ALL 3 million observations to evaluate the expression in parentheses, which can be very time consuming (and sort of defeats the purpose). Is there a way to only read the first 100 observations without having to evaluate the entire dataset? Perhaps some application of the "set obs 100"? But I have not been successful. Thank you. -Mark ---------------------------------------------- Mark Rodini mrodini@compasslexecon.com * * 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/

**Follow-Ups**:**Re: st: using the first n observations in a dataset w/o evaluating the whole thing?***From:*David Kantor <kantor.d@att.net>

**st: RE: using the first n observations in a dataset w/o evaluating the whole thing?***From:*"Kieran McCaul" <kamccaul@meddent.uwa.edu.au>

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