search for: z_12

...g among others y=f(x1)+f(x2) vs y=f(x1)+f(x2)+f(x1,x2) (testing for additivity) In mixed model representation, where X represents the unpenalized part of the spline functions and Z the "wiggly" parts, this would be: y=X%*%beta+ Z_1%*%b_1+ Z_2%*%b_2 vs y=X%*%beta+ Z_1%*%b_1+ Z_2%*%b_2 + Z_12 %*% b_12 where b are random effect vectors and the hypothesis to be tested is H_0: Var(b_12)=0 (<=> b_12_i == 0 for all i) the problem: gamm() does not seem to support the use of nested tensor product splines, does anybody know how to work around this? example code: (you'll need to s...

I am using the lattice packge for its levelplot and contourplot. Is it possible to adjust the line thickness of the 'box' and tickmarks in these plots? Thanks for the attention, Matt Sundling