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
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