RE: Puzzled by the "Variance"
- To: mathgroup at smc.vnet.net
- Subject: [mg86576] RE: [mg86506] Puzzled by the "Variance"
- From: "Jaccard Florian" <Florian.Jaccard at he-arc.ch>
- Date: Thu, 13 Mar 2008 20:55:04 -0500 (EST)
- References: <200803121029.FAA17511@smc.vnet.net>
You've got a lot of very good answers...
As a complement:
In earlier versions, you could also ask for the biased (or population)
variance. It still works with v.6, in spice of the fact that it's
considered as "removed"...
Just write:
data = {1, 2, 3};
<< "Statistics`"
VarianceMLE[data]
It gives: 2/3
But it's quite dangerous to use "removed" mathematica packages...
I just don't understand why Wolfram removed this function... In most
other systems, you can ask for both variances!
Florian Jaccard
-----Message d'origine-----
De: Elements [mailto:philyer at gmail.com]
Envoy=E9=A0: mercredi, 12. mars 2008 11:29
=C0=A0: mathgroup at smc.vnet.net
Objet=A0: [mg86506] Puzzled by the "Variance"
Greeting all
I'm puzzled by the function "Variance". We can learn how to calculate
variance from this =
page:http://mathworld.wolfram.com/SampleVariance.html.
For example, calculate the sample variance of {1,2,3}. the average of
{1,2,3} is 2, then the variance should be =
((1-2)^2+(2-2)^2+(3-2)^2)/3=2/3.
But mathematica gives that:
In[10]:= Variance[{1.0,2.0,3.0}]
Out[10]= 1.
Why??
--
Best Wishes!
Yours Sincerely
- References:
- Puzzled by the "Variance"
- From: Elements <philyer@gmail.com>
- Puzzled by the "Variance"