I see I made a mistake in my previous mail, the median should be 3 of course not 2 (forgot to sort ;)).
How exactly do you define the nth percentile? When you have an uneven number of elements and you take the 50th percentile, do you leave of (n-1)/2 elements or the (n+1)/2 elements? I believe that you leave of (n-1)/2 elements in rrdtool's implementation. I'm not sure which one is more correct... So the relation with the median: if there are an uneven number of elements you give the array[(n-1)/2] element which is the median. If there are an even number of elements you also give array[(n-1)/2] but the median would be the average between array[(n-1)/2] and array[(n-1)/2]. I'd say that for a median you can use the 50th percentile, it's a good approximation :) Alex -- Unsubscribe mailto:[EMAIL PROTECTED] Help mailto:[EMAIL PROTECTED] Archive http://lists.ee.ethz.ch/rrd-users WebAdmin http://lists.ee.ethz.ch/lsg2.cgi
