Alpha-scale covariance for a frozen-margin association

Returns the association-coefficient block of the two-stage Godambe covariance for an admitted fixed-effect complete-pair association. Standard errors are sqrt(diag(vcov(object))). The covariance and standard errors are on the unbounded association-link (alpha) scale, not the bounded latent association (eta) scale. The method warns when coverage is uncalibrated or the fit lies outside the retained coverage domain, and errors rather than manufacturing a covariance when fit-specific diagnostics fail.

Usage

# S3 method for class 'drm_pair_association'
vcov(object, ...)

Arguments

object

A fitted drm_pair_association object.

...

Reserved for future options.

Value

A named symmetric covariance matrix for the alpha coefficients.

See also

confint.drm_pair_association()