Hi Winfried, On Thursday, 2017-09-14 09:18:23 +0200, Winfried Donkers wrote:
> As we now have changed GEOMEAN, I think it would be wise to try to improve > ODFF1.2 as well for GEOMEAN. > > Verzonden: woensdag 26 juli 2017 12:06 > > Geometric mean is defined as n-root( a1 * a2 * ... * an). This applies for n > positive values a#. > This is awkward to compute as overflow is lurking in case of large values a > and a large number n. > An alternative computation is given in ODFF, but the case of any value a# > being 0 is not mentioned (result is then 0). > Any a# with value is a geometrically valid situation, unlike negative values > which do not have any geometric meaning AFAIK. > > I would propose an amendment of ODFF1.2 for GEOMEAN: > Constraints: numbers >= 0 > Semantics: addition of Returns zero when one or more numbers have value 0. > > What's your opinion? Isn't it rather that the product of all a# must be >=0 because of the rootN? Without reading statistics I have no idea if a single negative value may make sense for GEOMEAN or is actually an error (like it is treated today by both Calc and Excel). Do you happen to know? Eike -- LibreOffice Calc developer. Number formatter stricken i18n transpositionizer. GPG key 0x6A6CD5B765632D3A - 2265 D7F3 A7B0 95CC 3918 630B 6A6C D5B7 6563 2D3A Care about Free Software, support the FSFE https://fsfe.org/support/?erack
signature.asc
Description: PGP signature
_______________________________________________ LibreOffice mailing list LibreOffice@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/libreoffice
