Re: PSPP-BUG: 'Undo" function in PSPP?

[John Darrington]

On Tue, Oct 05, 2021 at 09:40:10PM +0000, Lane, Jonathan D. wrote:

     Thank you for maintaining and updating PSPP. There doesn't appear to be
     an "undo" function in the 9-5-2020 version of PSPP for Windows. "Undo"
     and "Redo" buttons/functions are common features of most programs. Is
     there indeed an "undo" function in the program?

Short answer: Not in the place that you're probably wanting it.

There is an Undo/Redo feature in the syntax editor, so that you can Undo/Redo
edits you have made there.

There is no such feature for the data editor, for a simple reason:  Since
transformations in the data editor are in general non-reversable, the only
way to implement such a feature would be to keep a copy of the entire dataset,
so that it can be restored on Undo.   Datasets in PSPP can be enormous - larger
than the available memory of the machine, and in the case of datasets which
come from external sources such as a database connection, large that the local
machine's disk.  A copy would need to be kept  before every transformation, 
which
for a large dataset would rapidly exhaughst the space needed to keep it.

J'