Am 23.02.2022 um 23:31 schrieb Riccardo (Jack) Lucchetti:
 On Wed, 23 Feb 2022, Sven Schreiber wrote:
> To whom it may concern: There's now a new dollar accessor $panelpd which
> provides that information (returns NA if it's not a panel dataset). This
> will be documented shortly.
 Just to clarify: this is in the development version. Thie feature will
 appear in gretl version 2022b. 
Right, since this thread started before 2022a came out, that's probably
a useful clarification.
I've just added an entry to the function reference (in git master).
Please check if it's OK.
thanks
sven