varFixed class,
representing a variance function with fixed variances. Letting v
denote the variance covariate defined in
value, the variance
function s2(v) for this class is
s2(v)=|v|. The variance covariate v is
evaluated once at initialization and remains fixed thereafter. No
coefficients are required to represent this variance function.
varFixed(value)
v. Grouping factors are ignored.
varFixed object representing a fixed variance function
structure, also inheriting from class
varFunc.
You can use the functions
varWeights and
coef to extract the weights and coefficients, respectively, from a
varFixed variance function structure. For more details, see the links below for the generic functions
varWeights and
coef.varFunc.
vf1 <- varFixed(~age)