[R] gam parameter predictions

[Luis Ridao Cruz]

R-help,

I'm applying a gam model (package mgcv) to predict
relative abundances of a fish species.

The covariates are year, month, vessel and statistical rectangle.


The model looks like this:

g1 <- gam(log(cpue) ~  s(rekt1) + s(year) + s(mon) + s(reg1), data =
dataTest)


Once the model is fitted to the data I want to get the mean model
estimates by year.

I do the following:

obsPred <- data.frame(year = dataTest$year, pred = predict(g1, type =
"response"))

gamFit <- tapply(obsPred$pred, list(year = obsPred$ar), mean)



Is this correct?



Thanks in advance


> version
               _                           
platform       i386-pc-mingw32             
arch           i386                        
os             mingw32                     
system         i386, mingw32               
status                                     
major          2                           
minor          4.1                         
year           2006                        
month          12                          
day            18                          
svn rev        40228                       
language       R                           
version.string R version 2.4.1 (2006-12-18)