vector of character strings for names of 'real' parameters
newdata
dataframe of predictor values
byrow
logical for whether to compute covariances among 'real' parameters for each row of new data, or among rows for each real parameter
...
other arguments (not used)
Value
A matrix containing the variances and covariances among beta parameters
on the respective link scales, or a list of among-parameter variance-covariance
matrices, one for each row of newdata, or a list of among-row variance-covariance
matrices, one for each 'real' parameter.
Details
By default, returns the matrix of variances and covariances among the
estimated model coefficients (beta parameters).
If realnames and newdata are specified, the result is
either a matrix of variances and covariances for each 'real' parameter
among the points in predictor-space given by the rows of newdata
or among real parameters for each row of newdata. Failure to
specify newdata results in a list of variances only.