[gmx-users] g_energy => RMSD = Standard Deviation?

[Tsjerk Wassenaar]

Hi,

It also doesn't hurt to read up more about statistics. The standard
deviation is the square root of the second central moment of a
distribution, so it's the expectation value for the average deviation
found in a set of mutually indepent data points. Root mean square
deviation does not imply mutual independence of data points, so, no,
it is not equal to the standard deviation, except when you have a
suitable data set. For a time series you'd have to correct for
autocorrelation to get the standard deviation. RMSD is just easier.

Cheers,

Tsjerk

On Fri, Jun 19, 2009 at 12:57 AM, Justin A. Lemkul<jalemkul at vt.edu> wrote:
>
>
> Chih-Ying Lin wrote:
>>
>> HI
>> After  the command g_energy =>
>> the value of RMSD is shown,
>>
>> I can not find the math definition of RMSD from manual.
>> Is the math definition of RMSD = Standard Deviation in Statistics?
>>
>
> First Google result for "root mean square deviation":
>
> http://en.wikipedia.org/wiki/Root_mean_square_deviation
>
> -Justin
>
>> Thank you
>> Lin
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>
> --
> ========================================
>
> Justin A. Lemkul
> Ph.D. Candidate
> ICTAS Doctoral Scholar
> Department of Biochemistry
> Virginia Tech
> Blacksburg, VA
> jalemkul[at]vt.edu | (540) 231-9080
> http://www.bevanlab.biochem.vt.edu/Pages/Personal/justin
>
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-- 
Tsjerk A. Wassenaar, Ph.D.
Junior UD (post-doc)
Biomolecular NMR, Bijvoet Center
Utrecht University
Padualaan 8
3584 CH Utrecht
The Netherlands
P: +31-30-2539931
F: +31-30-2537623