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*Subject*: **Re: [office-comment] RSQ - Unstable Algorithm**

*From*:**Leonard Mada <discoleo@gmx.net>***To*: office-comment@lists.oasis-open.org*Date*: Fri, 06 Jul 2007 22:17:58 +0300

Hello I noticed that the algorithms used for the various OOo Calc functions have been recently improved/corrected [including RSQ() ]. While I sneaked through the code, it struck me the simplicity of the RSQ() implementation. Indeed, RSQ() is the *square of the Pearson coefficient*, so I wonder: *Why does the OASIS document contain that awful formula instead of the straightforward one*? I verified in the last hour that the 2 formulas are indeed *mathematically identical*, so I am really puzzled. The square of the Pearson coefficient is simply: r^2 = { sum[(Xi - Xm)(Yi - Ym)] }^2 / {sum[(Xi - Xm)^2] * sum[(Yi - Ym)^2] } Indeed, just take the square of the Pearson coefficient!!! [IF somebody is interested in the mathematical calculations, give me a short notice, BUT I'll need a couple of days to type it on the computer.] [The used formula did *MISLEAD* me, too. I thought it is some really weird function.] Is there any reason to use that complex and incomprehensible formula, instead of the simple and straightforward one? Sincerely, Leonard

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