search for: gcvplot

Displaying 2 results from an estimated 2 matches for "gcvplot".

2007 Jun 04
0
Local polynomial regression using locfit
...values for multiple years (and ages, not included) with missing years. I would like to use local polynomial regression to smooth the values and estimate for the missing years. I would also like to use GCV to justify the smoothing parameter selection. When using locfit() with lp() I found that the gcvplot function does not work as it is looking for an alpha value to replace so I used gcv(): ######################################################################## # library(locfit) ### approx. my data Year= c(1954,1965,1966,1967,1968,1969,1970,1978,1979,1980,1981,1982,1985,1987, 1988,1989,1990,1991,1...
2005 Nov 17
3
loess: choose span to minimize AIC?
Is there an R implementation of a scheme for automatic smoothing parameter selection with loess, e.g., by minimizing one of the AIC/GCV statistics discussed by Hurvich, Simonoff & Tsai (1998)? Below is a function that calculates the relevant values of AICC, AICC1 and GCV--- I think, because I to guess from the names of the components returned in a loess object. I guess I could use