A smooth of `disbinary' doesn't really make sense. It should enter the model parametrically. The problem is easy to see in 1D. Consider the model y_i = f(x_i) + error_i where `f' is a smooth function. If x_i only takes the values 0 and 1 then you really don't have much of a basis for estimating f.
>- Simon Wood, Mathematical Sciences, University of Bath, Bath BA2 7AY >- +44 (0)1225 386603 www.maths.bath.ac.uk/~sw283/ On Thu, 13 Dec 2007, zhijie zhang wrote: > Dear all, > Following the help from gam(mgcv) help page, i tried to analyze my > dataset with all the default arguments. Unfortunately, it can't be run > successfully. I list the errors below. > > #m.gam<-gam(mark~s(x,y)+s(lstday2004)+s(slope)+s(ndvi2004)+s(elevation)+s(disbinary),family=binomial(logit),data=point) > > m.gam<-gam(mark~s(x,y,k=10)+s(lstday2004,k=10)+s(slope,k=10)+s(ndvi2004,k=10)+s(elevation,k=10)+s(disbinary,k=10),family=binomial(logit),data=point) > >> m.gam<-gam(mark~s(x.1,y.1,k=10)+s(lstday2004,k=10)+s(slope,k=10)+s(ndvi2004,k=10)+s(elevation,k=10)+s(disbinary,k=10),family=binomial(logit),data=point) > #?????? > Errors: smooth.construct.tp.smooth.spec(object, data, knots) : > A term has fewer unique covariate combinations than specified maximum > degrees of freedom. > > #========================# > Descriptions for my dataset > #========================# > There are 1 response variable "mark" (1-case,0-control), and 7 explanatory > covariables. > x/y are spatial coordinates, > lstday2004, slope, ndvi2004, elevation: continuous variables; > disbinary : binary variable. > Is there any problems with the above codes? How should i solve it? > Any help or suggestions are greatly appreciated. > -- > With Kind Regards, > > oooO::::::::: > (..)::::::::: > :\.(:::Oooo:: > ::\_)::(..):: > :::::::)./::: > ::::::(_/:::: > ::::::::::::: > [***********************************************************************] > Zhi Jie,Zhang ,PHD > Tel:+86-21-54237149 > Dept. of Epidemiology,School of Public Health,Fudan University > Address:No. 138 Yi Xue Yuan Road,Shanghai,China > Postcode:200032 > Email:[EMAIL PROTECTED] > Website: www.statABC.com <http://www.statabc.com/> > [***********************************************************************] > oooO::::::::: > (..)::::::::: > :\.(:::Oooo:: > ::\_)::(..):: > :::::::)./::: > ::::::(_/:::: > ::::::::::::: > ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
