Is it possible to execute a program within another program that requires parameters? (without inlining it)
E.g.
________________
- PROGRAM:ADD
- :Prompt A,B
- :A+B>C
________________
- PROGRAM:TEST
- :For(I,0,20)
- :Disp (prgmADD (I,I+1))
- :End_________
Obviously this doesn't work the way it currently is, but I hope I made it clear what I'm getting at.
The conventional way to pass arguments is in a list through Ans like so:
________________
- PROGRAM:ADD
- :Ans(1)+Ans(2
________________
- PROGRAM:TEST
- :For(I,0,20
- :{I,I+1
- :prgmADD
- :Disp Ans
- :End
________________
I don't think there is a way to do that - you're basically asking to fake user input, which isn't supported.
The way I have gotten around it is preloading the variables by setting A and B to I, I+1. Then have another variable that you never touch in any program that is a flag letting the subprogram know it can skip input.
When the subprogram runs, it uses an if statment to check the flag variable. If it is set to a specific value you've chosen, it knows that it means it doesn't have to run the Prompt command because A and B are already set. After checking the value, it should reset the flag so that when you run it manually later it doesn't skip the prompt.
The specific convention I used was to have the last list in the system reserved for use by my programs. Each program knew to look at the list for parameters. That made it so I didn't have to worry about getting variable letters matched up between programs. So in this case the first element of the list could be 1 to signal that there are parameters to read. If it is 0, it uses prompt. Otherwise it looks at the second and third elements for the values of A and B. It clears the list when it is done with it, so the leftover data doesn't interfere with later runs.
As Katie stated, there is no built in method for passing parameters between TI-Basic Programs. There is, however, a primitive method through which a single parameter can passed to a function.
An unevaluated expression can be held in one of the Y-VARS variables. Using this variable in your program will cause the expression contained within to be evaluated and the result to be returned. The interesting part of this is that Y-VARS variables can be passed a parameter which will be substituted for a single variable in the body of the expression. The variable that it is substituted for depends on the Y-VARS variable you used. Function variables use X, Parametric use T and, Polar use θ.
This Sample program demonstrates what I have described.
:"XLog(X→Y1
:Disp Y1(10
:Disp Y1(5
When Y1 is passed 10 as a parameter, all instance of X in Y1 are replace with 10. Y1 is now equivalent to 10log(10, or simply 10. The same affect is seen when passing 5 to Y1.
The obvious drawback of this workaround is that only one parameter can be passed. Other drawbacks include that you can only put standard calculator functions into one of the Y-VARS and that accessing Y-VARS comes with a significant overhead.
