-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Dear Qixu,
there is no contradiction in your quotes and what you are thinking: * "The standard deviation has the same unit as the values you're measuring." * I always think that the unit of deviation is the same to the values we're measuring. this fits, don't you see? Cheers, Tim On 04/24/12 05:21, Qixu Cai wrote: > Dear Johan, > > "the standard deviation is defined as the square root of the > variance." while "The standard deviation has the same unit as the > values you're measuring." > > So we can say what's the unit of deviation? Is it the square of the > unit of standard deviation? > > I always think that the unit of deviation is the same to the > values we're measuring. Maybe I make a mistake... > > Thank you very much! > > > > On 04/24/2012 10:30 AM, Johan Hattne wrote: >> Hi Qixu; >> >> This is by definition--the standard deviation is defined as the >> square root of the variance. >> >> http://mathworld.wolfram.com/StandardDeviation.html >> >> The standard deviation has the same unit as the values you're >> measuring, which makes its interpretation a tad easier. >> >> // Best wishes; Johan >> >> >> On 23 Apr 2012, at 18:13, Qixu Cai wrote: >> >>> Dear Ed, >>> >>> Why the variance is the square of standard deviation? >>> >>> thank you very much! >>> >>> >>> 在 2012年4月23日，20:53，Ed Pozharski<[email protected]> 写道： >>> >>>> On Sun, 2012-04-22 at 12:47 +0530, Arka Chakraborty wrote: >>>>> baverage program in ccp4 gave average bfactor of 25.0 for >>>>> the residue but coot is showing 150! >>>> Variance is the square of standard deviation, thus var=150 >>>> means sigmaB~12 in that particular residue. High, but not >>>> impossible. >>>> >>>> -- I don't know why the sacrifice thing didn't work. Science >>>> behind it seemed so solid. Julian, King of Lemurs >> Postdoctoral Fellow @ Physical Biosciences Division >> __________________________________________________________________ >> >> Lawrence Berkeley National Laboratory * 1 Cyclotron Rd. >> Mail Stop 64R0121 * Berkeley, CA 94720-8118 * +1 (510) 495-8055 >> >> > - -- - -- Dr Tim Gruene Institut fuer anorganische Chemie Tammannstr. 4 D-37077 Goettingen GPG Key ID = A46BEE1A -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iD8DBQFPll3YUxlJ7aRr7hoRAoOfAJ4kh9s7MryWp9u53dFudMLzbCkT9wCfZ+gV kTkvc8sma3Z8Ym/9n5JkuOw= =d+ug -----END PGP SIGNATURE-----
