[R] How does predict.loess work?
David Winsemius
dwinsemius at comcast.net
Wed Apr 4 00:01:04 CEST 2012
On Apr 3, 2012, at 4:12 PM, Recher She wrote:
> Dear R community,
>
> I am trying to understand how the predict function, specifically, the
> predict.loess function works.
>
> I understand that the loess function calculates regression
> parameters at
> each data point in 'data'.
>
> lo <- loess ( y~x, data)
Well, it produces a fitted-value at each point. Whether there are
parameters at each point might depend on the degree of the fit.
>
> p <- predict (lo, newdata)
>
> I understand that the predict function predicts values for 'newdata'
> according to the loess regression parameters. How does predict.loess
> do
> this in the case that 'newdata' is different from the original data
> x? How
> does the interpolation take place?
Type this at your console:
getAnywhere(predict.loess)
And after seeing that an additional functions is called type this:
getAnywhere(predLoess)
And then you will see that you have descended into a C function called
'C_loess_dfitse'.
>
> [[alternative HTML version deleted]]
--
David Winsemius, MD
West Hartford, CT
More information about the R-help
mailing list