OptionaldfDegrees of freedom of the t tests. Default: the residual degrees of freedom for an lm fit and Infinity (z tests)
for a glm fit, of every family (lmtest's default; glmSummary uses t tests for the families with an estimated
dispersion). A value that is not positive and finite gives z tests.
OptionalvcovThe covariance of the coefficients. Default: the fit's own (R's vcov(fit)), with NaN for aliased coefficients.
Options for coeftest.