RE: Re: UNDO and Mathematica - how useless is it?

*To*: mathgroup at smc.vnet.net*Subject*: [mg98049] RE: [mg98023] Re: UNDO and Mathematica - how useless is it?*From*: "David Park" <djmpark at comcast.net>*Date*: Sun, 29 Mar 2009 02:42:34 -0500 (EST)*References*: <200903251042.FAA24502@smc.vnet.net> <23582715.1238067049865.JavaMail.root@m02> <17153368.1238240355160.JavaMail.root@m02>

Yes, often the perfect is the enemy of the useful. I would think it would be enough to just undo text editing. I wouldn't even worry about the 4-day calculation. It is not that common, and if it is important to save it then the user could have saved it in a file. And if an UNDO changed the Input cell then maybe the calculation was no good anyway. David Park djmpark at comcast.net http://home.comcast.net/~djmpark/ From: Bob F [mailto:deepyogurt at gmail.com] It seems that because the problem is difficult to provide a "perfect" solution, the currently worthless solution is any better? What would be bad about providing an UNDO that only worked on the state of the text that forms the notebook or cell? That way any change could be undone, and if needed then a simple re-execution of the cell/ notebook would get the old calculation back. Yes, I realize what about if the calculation took 4 days to complete, you surely dont want to undo that if the result is truly valid, but perhaps a cell could be marked as "Don't Change with UNDO" or something like that (just like you can mark it as visible or editable or ???) Would this give people all the ability of a multi-level undo without the possibility of loosing valuable calculations?? -BOB

**References**:**UNDO and Mathematica - how useless is it?***From:*Bob F <deepyogurt@gmail.com>