Variance in Statistics interface

maalvarez

Hi,

I need help about the variance statistic.
I see that RapidMiner has a statistic interface called Statistics (http://rapid-i.com/api/rapidminer-5.1/com/rapidminer/example/Statistics.html).

This interface has a VARIANCE field, but I unknow the exact definition of this variance.
For example, is this field like the next formula?



Or is the next?



Thanks.

land

Hi,
actually these two formula just express the same. The first for the empirical case, where you have a finite number of samples from a distribution and the second one for the theoretical case.
As RapidMiner just works on the samples of the example set, it uses the first one.

Greetings,
Sebastian