Plot the residuals against the fitted values for a copulareg object, or predicted values against the prediction error
# S3 method for copulareg plot(x, new_x = NULL, new_y = NULL, ...)
Model fit as returned by copulareg
optional matrix of covariate values to compute the predicted values of the outcome for. If not specified, the fitted values for the training sample are used.
Optional vector if the plot should show predicted values and prediction error.
additional parameters to plot.
No return value, called to produce plot.