On Jan 18, 2012, at 3:07 PM, kcrisman wrote: >>>>>>> Of course any bug reports or suggestions are very welcome. In >>>>>>> particular checking my initial examples would be helpful. Some screen >>>>>>> shots are available athttp://boxen.math.washington.edu/home/iandrus/ >> >>>>>> Nice! >> >>>>>> As a question from someone who does not own an iDevice... how is this >>>>>> working? Single-cell server, or some other mechanism? Do objects >>>>>> persist, or is it more of a calculator option? (I assume you aren't >>>>>> compiling all of Sage on an iPhone...) >> >>>>> It uses the Single-cell server to do the calculation, but persists the >>>>> objects. Compiling all of Sage would be lots of work and wouldn't make >>>>> it past Apple's review process. >> >>>> Hmm. Jason said that the point of the single-cell was that objects >>>> don't persist. How do you do that? (On the phone, I assume?) >> >>> Well, static output persists (in that you can ask for the session output >>> for any session and it is still in the database). At least, right now we >>> don't purge the database periodically. But you're right that the session >>> doesn't stay active. >> >> I misspoke. We don't persists objects per se, but rather save the input and >> output for future perusal. > > So, to hijack this thread, let me get complete clarity about what the > single-cell server does. > > 1) You send it a computation. To make it relevant to this discussion, > let's say > > A = 2+2; A > > 2) It returns the output of the computation, in this case > > 4 > > 3) Ivan's app has saved both of these, but the single-cell has > "forgotten" about the input. > > 4) Someone else uses the single-cell for something in the meanwhile, > computing perhaps > > A = 3+3; A > > which changes the value of A in the single-cell (or maybe there is no > "current" value for A, it needs to be redefined?). > > 5) The first person, using Ivan's app, now wants > > A+1 > > and the single-cell does *not* look in some database for A, nor does > it use the changed value A=6 (if that even is what happens). Instead, > the app magically knows to resubmit the whole > > A = 2+2; A > A+1 > > returning > > 5 > > OR does it take the return value for A, which is 4, and then > substitute that in somehow? (Which, given the "criticism" some have > lodged that you can't always take print values for Sage objects and > put them back in computations, could fail for things like matrices.) > > Or is something else what happens? > > +++ > > The reason I ask is that I had multiple requests about the single-cell > at the Joint Meetings table, and in particular this issue of > persistence came up for one gentleman (Jason, I think you spoke with > him too). I strongly suspect that some of the other users of the > single-cell wouldn't mind this, either, though their uses are more > amenable to the once-off computations. But if we had some really > clear documentation for how to "simulate" persistence in the way Ivan > is, that could be very useful - for instance, Volker's Android app > could probably use it (?).
The only thing the iPhone app (currently) does is save the text input and output (as well as images). So if you want A+1, you copy the cell and add A+1 to the end (or you edit the cell and add A+1 to then end) and then run the whole computation over. It's not ideal in many ways, but it makes it very easy for quick computations and if you want to do more complicated things you should probably be using a notebook IMHO. I guess you could say that I save notebooks which have a limit of one cell. It would certainly be possible to add multiple cells, but if I do that then I think we should just use the notebook (making whatever improvements are necessary for use on mobile devices). I realize it's easy to start with a simple calculation and then want more, so I want to add a "Convert to Notebook" button, but I want to get version 1 out there before I tackle that (although it's probably very easy). But of course we'll do what is useful for people. -Ivan -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
