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From |
Maarten Buis <maartenlbuis@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: egen anycount |

Date |
Wed, 25 May 2011 11:15:38 +0200 |

On Tue, May 24, 2011 at 9:03 PM, Thomas Speidel wrote: > The reality is much less picture perfect: a MET value is assigned from a > published compendium of physical activities. This compendium has a single > decimal point of precision (just like the last page on the Wikipedia > article). Of course, if I had a choice I would do the calculations myself, > thus preserving more accuracy, but I have to rely on published sources and > work within its constraints. > I suspect you are going to suggest using reshape... :-) No, if you want to make use of >= or <= or == evaluations, and you really care about those equal signs, than you must code those activities as 10*MET values. These will be integers and thus stored precisely. The distinction here is between precise measurement (which you do not have, but the same is true for most of us) and precise storage. It is the latter that gave you trouble when you tried to evaluate -variable >= some number-. This advise of coding 1.1 as 11 and 1.2 as 12, etc works because you have exactly one number behind the decimal point. If the numbers happen to money in euros or dollars and you wanted them to be accurate up to the cent, you would store those number in 100*dollars or 100*euros (i.e. in cents). The trick is that computers can store integers exactly, so if there is a fixed number of numbers behind the decimal point you can store those numbers exactly by multiplying with the appropriate power of 10 that will turn them into integers. Hope this helps, Maarten -------------------------- Maarten L. Buis Institut fuer Soziologie Universitaet Tuebingen Wilhelmstrasse 36 72074 Tuebingen Germany http://www.maartenbuis.nl -------------------------- * * 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**:**Re: st: egen anycount***From:*daniel klein <klein.daniel.81@googlemail.com>

**RE: st: egen anycount***From:*Nick Cox <n.j.cox@durham.ac.uk>

**RE: st: egen anycount***From:*Thomas Speidel <thomas@tmbx.com>

**RE: st: egen anycount***From:*Nick Cox <n.j.cox@durham.ac.uk>

**RE: st: egen anycount***From:*Thomas Speidel <thomas@tmbx.com>

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