[R] locfit smoothing question (package maintainer not reachable)

Suresh Krishna madzientist at gmail.com
Wed Mar 4 13:41:28 CET 2009

On Tue, 03 Mar 2009 22:10:42 +0100, David Winsemius  
<dwinsemius at comcast.net> wrote:

> That is what I thought to be the critical paragraph. The variance is  
> assumed to be = 1 when you use family="gaussian" rather than the default  
> of family="qgauss". You give it a vector, 1000*rnorm(100), that ranges  
> widely and a small (relative) variance is assumed and so the confidence  
> intervals are plotted as very narrow. This does not seem surprising  
> given the functions documented design. I have the book and do not think  
> I even need to pull it off the shelf since the help pages appear fully  
> informative in this instance. I get an rv of 1 with the "gaussian"  
> option and an rv of nearly 1000 when the default is used.

Thank you, that is helpful. I guess I am wondering under what circumstance  
would it be appropriate to assume that the data had a variance of 1 and  
use the family=gaussian option. Perhaps this is for normalized data ?


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