In a few weeks, I will be going to Puerto Rico to visit family. That would be all fun if it wasn't for one thing: The Long Plane Ride! While brain-storming ideas about what to do with my year-old TI-84+ SE, I thought of an idea: a gCn enabled CAS that would learn from user-input. Although only Cemetech staff or a group of math whizzes could actually 'teach' the program. In return for me coming up with the pseudocode and some very basic code by the time I get back, I would at least like a veribality test on how this program would work and/or be need to be coded. My best programming abilities are with TI-Basic and Axe. So, unless anyone has a better idea, it would be programmed in Axe. I know people might say, "This is a very ambitious project." I provide a solution: open-source. Whenever I, or someone else, makes an improvement to the code, that improvement would be posted here in this thread (KermM, for example would improve the gCn capabilities). I would very much like comments about the CAS. Even a name for the program would be helpful.

why would you need gCn to make a CAS? they dont really have much to do with each other...?

so that it could teach itself. Althoug gCn would not HAVE to be used, it would just be used to teach the CAS program.

oh, like some kind of update system. mmm, why not just release patches on ticalc and use Kerm's super awesome sandpaper client to update the program definitions?

guess it could work, but being ambitious me, I would like gCn enabled.

make it to where there is an option to turn this off, too. that way, the program can go directly into CAS Mode without checking to see if gCn is available and trying to grab an update.

great idea! see I told my brother this thread would help my idea (hes a pessimistic 5th grader).
EDIT: after a disscusion on SAX, gCn has been dropped. but may be implemented as a side feature.

I got the beginning code ready for FOILing:

Code:

I know it's not pure Axe, but it's psuedocode and it is easier to visualize this way.
Also, I don't really know what else needs to be included in a CAS so if anyone would like to make those sections or voice what those sections are, please post them.

Alright, my brain is killing me. I tok two Tylenol and nothing is helping. Not even me trying to make pseudocode for factoring trinomials. I DO NOT have any clue on how to do this. PLEASE HELP ME! (on an unrelated note, I will have some free time in two weeks to improve code). Anyway, please post CAS related equations to put into the program.
EDIT: Got the final FOIL formula finished during a trip to the barber.

Code:

Remember, 'x' is used as an unkown.

Well, generally a CAS is a lot more general. It first takes an equation in symbolic string form (like ax+b(c+dx)), performs operations called lexing and parsing to reduce the input to some kind of tree (here, first add c and d times x, then multiply the result by b, then add that result to a times x). Then, it can use a set of rules to simplify. For example, using constant multiplication rules, it can simplify to ax+bc+bdx (in its tree form, not in string form). Next, it can combine coefficients to get (a+bd)x+bc. Finally, it can see there are no more simplifications to apply, convert its tree (or AST) back to a string, and show that to the user.

That makes it so much easier to understand. Thank you. (memo to self, ask Kerm more and rely on Wikipedia's list of CAS includes less).

You could always look into the gCAS/gCAS2/Graph3DP threads.

For how trees can be used for math, look at a gif generated by gCAS2 doing evaluation:

this thread's topics are going to be moved to the 'my projects' thread.
Please don't post here and instead post here -> http://www.cemetech.net/forum/viewtopic.php?t=9259