May I be permitted to ask this again in the hope of obtaining an answer?

Clearly I'm missing something obvious, but how does one do this? Correlating the variable with the model residuals to assess this is, I believe, incorrect.

I consulted the guide and turned up dry, ditto the command reference. Running the coefficient covariance matrix doesn't include the residuals. I've also run a Google search and could only find this:

http://lists.wfu.edu/pipermail/gretl-users/2011-July/006470.html

which isn't quite what I'm looking for. This should be straightforward, so your assistance would be very much appreciated.

-- 
Clive Nicholas

"My colleagues in the social sciences talk a great deal about methodology. I prefer to call it style." -- Freeman J. Dyson