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

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

Subject |
st: RE: RE: Sum product of each element with each other element except itself? |

Date |
Sun, 16 Aug 2009 16:52:59 +0100 |

It sounds as if you just keep going, using the principle that sum of (everything - somethings) = sum(everything) - sum(somethings). Nick n.j.cox@durham.ac.uk Martin Weiss This FAQ may be helpful: http://www.stata.com/support/faqs/data/members.html Apart from that, give an excerpt of your data, and show exactly what you want to happen to it... Stata Chris I would like to compute the following in Stata: Sum over all n of: Sum over all m unequal n of: (D_nt - p)*(D_mt - p), where m, n, t are subindices. If it was with only a single sum and without the unequal condition, I would just have used sth like this: bysort m n t: gen factor1 = (D_nt - p) bysort m n t: gen factor2 = (D_mt - p) bysort t: egen result = sum(factor1*factor2) But I'm not sure how to get the product for each element n with each other element from the same set except itself. Should I do this with a loop or sth? * * 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: RE: RE: Sum product of each element with each other element except itself?***From:*Stata Chris <statachris@gmail.com>

**References**:**st: Sum product of each element with each other element except itself?***From:*Stata Chris <statachris@gmail.com>

**st: RE: Sum product of each element with each other element except itself?***From:*"Martin Weiss" <martin.weiss1@gmx.de>

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