This function is used internally by several survival routines. It
computes a simple quadratic form, while properly dealing with missings.
Usage
coxph.wtest(var, b, toler.chol = 1e-09)
Arguments
var
variance matrix
b
vector
toler.chol
tolerance for the internal choelsky decomposition
Value
a real number
Details
Compute b' V-inverse b. Equivalent to sum(b * solve(V,b)), except for
the case of redundant covariates in the original model, which lead to
NA values in V and b.