Lua check if device has CAS

[fredrik.ekelof]

Hi

Is it possible in Lua to verify/check that a program is running on a CAS unit, either hand held or software? I would like to avoid unexpected behavior of a program using CAS functions, running on non cas software.

The TI Lua API reference guide is a little cryptic on this matter. platform.hw() seems to return only 3 (hand held) or 7 (computer) independent of CAS. Command platform.getDeviceID() does not seem to return anything, anyway on the computer, so that will not work.

What happens if you try to run CAS commands on a non CAS unit in Lua, like math.eval("solve(x+2=4,x)")?

By testing to turn off CAS on my TI CX II-T CAS, and running solve(x+2=4,x) in the scratchpad returns a error popup stating like "limited capabilities when CAS is off". What would happen on a non CAS unit? By trying to run the same command from LUA it returns "nil 1327", however error code 1327 is not documented in the the TI CAS reference guide(latest version from TI web page). What error code would a non cas unit return?

[critor]

Hi.

Instead of using CAS functions (which are just going to trigger an error on non-CAS calculators), you may just calculate something.

For example, here's a TI-Basic function :

Code: Select all

Define iscas()=
Func
  Local p
  π→p
  Return getType(p)="EXPR"
EndFunc

You may then just call it from your Lua script : iscas = math.evalStr("iscas()").

[Adriweb]

The (almost) shortest answer for Nspire-Lua would be isCAS = not not math.evalStr('?') actually
You can set this global in an early-defined configuration or something, from on.resize for instance. Then you can just use "isCAS" wherever you need it.

(This was the topic of our first lua mini-challenge many years ago hah)

[fredrik.ekelof]

Thanks for your answers.

I will go for isCAS = not not math.evalStr('?') . This one was a really neat trick.