On May 3, 2013, at 10:58 PM, peter dalgaard wrote: > > On May 3, 2013, at 21:36 , David Winsemius wrote: > >> >> On May 3, 2013, at 10:46 AM, peter dalgaard wrote: >>> >>> >>> Because comparison with an unknown value yields an unknown result. >> >> Anything else would violate the Second Law of Thermodynamics. We cannot have >> comparisons reducing entropy, now can we? Uncertainty cannot run uphill. > > Now what does this say about SAS, where the missing value is smaller than all > regular numbers? I.e., > > DATA; > iteen = (age < 20); > > turns people of unknown age into instant teenagers.
And are handled as zero when included in calculations using SUM ( as, I also read, does SPSS). So SAS comparisons are still increasing entropy. Quantum mechanics says there is no real vacuum state, so maybe that's where those not-really-missing missing values are ending up after they confound our notions of existence. -- David Winsemius Alameda, CA, USA ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
