*From*: "Andreas J. Guelzow" <aguelzow taliesin ca>*To*: Gnumeric Dev List <gnumeric-list gnome org>*Subject*: Re: Median: Oasis and Fast Sorting Algorithm*Date*: Sat, 10 Feb 2007 10:46:42 -0700

On Sat, 2007-10-02 at 19:35 +0200, Leonard Mada wrote:

Lets assume the following space A={1,2,3} [I do not know if it is called space in English, probably NOT.] Lets take the array 1,1,2,3,3,3 So the median is (2+3)/2 = 2.5 ? BUT the space A does NOT have the value 2.5. It is either 2 or 3. In this case, it is more appropriate to talk about 2 medians, 2 and 3! And this list DOES NOT have the middle value of 2.5 because this value DOES NOT exist.

I am pretty sure that at least 99% of the spreadsheet users don't care about your space {1,2,3}. FOr them 2.5 exists.

Weighted Medians: actually, most real world applications making use of median from signal processing, use the weighted median. (Just google for "weighted median".) So again, because Excel did take the easy ride, I do NOT believe that a standard should follow the same way.

Excel, OOoCalc, Gnumeric, KSpread,... agree on what MEDIAN should alculate. The OpenFormula standard is not intended to invent new functions but to standardize these functions to allow for consistent interchange using the odf format. Perhaps there should be another function MEDIAN_MADA which would clearly need more arguments to allow for a specification of the space in question. Andreas Guelzow

-- Prof. Dr. Andreas J. Guelzow Dept. of Mathematical & Computing Sciences Concordia University College of Alberta

**References**:**Median: Oasis and Fast Sorting Algorithm***From:*Leonard Mada

**Re: Median: Oasis and Fast Sorting Algorithm***From:*Andreas J. Guelzow

**Re: Median: Oasis and Fast Sorting Algorithm***From:*Leonard Mada

**Re: Median: Oasis and Fast Sorting Algorithm***From:*John Machin

**Re: Median: Oasis and Fast Sorting Algorithm***From:*Leonard Mada

**Re: Median: Oasis and Fast Sorting Algorithm***From:*Andreas J. Guelzow

**Re: Median: Oasis and Fast Sorting Algorithm***From:*Leonard Mada

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