Re: Accuracy of Statistical Functions



Hello,

seems gnumeric is OK. :-)

If you receive this e-mail 2 times, take my apologies. I noticed too late that I sent it first to the wrong e-mail address.

Well, it was my fault as I opened the OOo ods document, and saw the results displayed as in OOo Calc, because gnumeric did *NOT recalculate* the formulas. Maybe there should be a method to recalculate the formulas in a document, especially IF the document was last *written* by a different application (I do NOT know if this can be read in the .ods document, though).

I noticed only today, that gnumeric is indeed more accurate. Good to know that! :-)

However, there are still some interesting points I discussed in the respective thread on the OOo mailing list (although the OOo developers were more or less reluctant for any fresh thoughts).

I have gnumeric 1.7.1, Windows edition (W2k SP4). I will make additional tests over the weekend, but until now it looks good for gnumeric.


Morten Welinder wrote:
Note, that sorting is not the greatest thing to do. For example if you have,
just three numbers

    small, +huge, and -huge

then you will actually want to add ┬▒huge and get zero before you look at
the small number

*Sorting* is a more general mechanism and should work good for many situation, not just for a small number of situations like the one mentioned above. But if actually the mathematical handling is more robust, its influence on accuracy won't be as big. I now believe that gnumeric is *quite robust* (and I saw the misleading values because gnumeric did NOT recalculate the formulas; sometimes shit happens).

The reason why sorting works is that, as you add the smaller numbers first, more less significant decimal places will be added, too, and may influence more significant digits. When you add larger numbers first, there is a higher chance to drop/round less significant digits.

Kind regards,

Leonard Mada



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