[R] problems with loess

[Prof Brian Ripley]

On Fri, 7 Oct 2005, Dimitri Giunchi wrote:

> Hi all,
> I was unable to obtained a smoothed line using the loess function.I used the following code reported in the examples of R documentation:
> cars.lo <- loess(dist ~ speed, cars)
> Then I tried to plot both the data and the smoothed line
> plot(cars)lines(cars.lo)
> but what I obtained is simply a broken line joining all the data points.I tried with different spans, but the results did not change.
>
> Does anyone know what's going wrong?

Yes. lines(cars.lo) plots the original data stored in the loess fit.

You need to predict, or use scatter.smooth to do it for you.

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
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