XCAS vs Prime

[Chris Pem10]

A few questions...

If we find a bug in XCAS, can we assume the same bug exists in the Prime CAS? And vice versa? I know this is not a simple question; but how similar are they? I remember a few instances on this list where a CAS bug got fixed and the author mentioned he applied the fix to XCAS as well.

Could you provide us a list of the parts of the CAS that need the most testing? If we're putting this device through its paces, might as well work on the most pressing needs first.

I haven't worked more than a few minutes withing the XCAS GUI, but it seems like that might be a more efficient place to find bugs if you can create "workbook" like calculations where each calculation builds on the preceeding work and you can save your work to test later.

I don't have much need for XCAS on the PC, as I have other programs I use, but if switching to XCAS for a few months will improve the Prime, I'm willing to put in some work.

Thoughts?

[Tim Wessman]

They are very similar except for two major distinctions.

1) There is no support for exceptions in the OS used for Prime. These are used primarily for erros and thus the behaviors there are sometimes different and not perfect.
2) There are less commands in Prime and some slight syntax differences where there were conflicts (%% vs % for example)


The primary area of weakness from my point of view are:

a) The simple things (XCAS is very powerful and does have a very high *capability* level, but the simple things which aren't in Bernard's area of focus have gotten the short end of the stick)
b) Inconsistencies where commands behave differently for unexpected or no apparent reason. Often, these seem to have been introduced for "convenience" but the overall effect makes the CAS less useable and understandable.

Note that this is not a criticism of XCAS which I am just *astounded* by, but rather my personal feelings having now used it for 2+ years.

[parisse]

Xcas and the Prime CAS Home and geometry app are two different UI for the same CAS kernel kernel giac (it has other UI now, like qcas on PC, Xcas Pad and Pocketcas on tablets, smartcas and xcas online in your browser, and also the geogebra CAS windows).
My expertise is in CAS not in UI, however since you can not attract users if you don't have a GUI, I had to implement a GUI for giac and that's Xcas. It is certainly far from perfect and it is commandline oriented (not the dominant philosophy in software, but I believe that our online help system is much more efficient than any other CAS I know: get a command from menu or type the first letters of a commandname, then tab and you have the short online help with description and examples ready to paste). It is certainly not intrinsically that difficult to learn since it is widely used in French highschools, my own experience with students is that they can do math computationnal exercices with Xcas after less than 1 hour (programming requires more time of course). Note that it's more difficult to learn Xcas if you are already used to another CAS. The English doc is unfortunately incomplete, the French doc is much better.