Loess Fit and Resulting Equation

r curve-fitting loess
christian miner picture christian miner · Nov 23, 2009 · Viewed 8.9k times · Source

I'm a developer up in Portland, OR. I'm wondering if anyone can assist:

I'm working on Loess fit models using R, once I have the fit accomplished, I'm looking to back-out the equation of the fitted non-linear curve, wondering if there is a way to determine this equation in R? I've been looking but can't find any literature. For me, the graph of the function is great, but without the equation of the graph, I'm kinda dead in the water.

Answer

Michael Dunn picture Michael Dunn · Nov 23, 2009

Loess doesn't give you an equation [1]. If you just want to get the values returned by the loess function you use predict(loess.object, new.data)

[1] From wikipedia:

Another disadvantage of LOESS is the fact that it does not produce a regression function that is easily represented by a mathematical formula. This can make it difficult to transfer the results of an analysis to other people. In order to transfer the regression function to another person, they would need the data set and software for LOESS calculations.

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