The discussion in #32 reminded me that one thing @andrewgelman and others have been wanting for a while (and that I think would also be useful as an alternative to the standard summary output) is a summary where each vector/matrix/array parameter only occupies a single line just like scalars. That is, each line corresponds to a named parameter rather than a parameter element.

(This could be its own thing or just an option to a custom print method for our existing summary objects.)

The quantities to display are debatable (e.g. maybe min of all the individual elements’ ESS, max of the Rhats, etc), so it would be good to get input from Andrew and anyone else interested.