Post your ideas for new science programs here, or build on ideas posted by other visitors.

Ok, so, I have gotten into writing programs for my calculator recently.

I was wondering if there was a way to get the calculator to solve for an unknown in a program.

For example:
the classic physics formula:

(Vf)^2 = (Vi)^2 + (2)(a)(d)
Vf = final velocity
Vi = initial velocity
a = acceleration (9.8 m/s^2)
d = distance

Say I was missing "d" from the formula and wanted the program to solve for it...but I have everything else. How do I program it to solve for "d", the missing variable, or any other variable that is not given?

I'd like to know this so I can write out some programs for my AP Physics calss on my own.

Any help is appreciated
My email is
crabnebula1@verizon.net

Thanks,

Chuck

This may not be the most elegant solution to your problem, but just don't show it to anyone if you're embarrassed about it, and it should work just fine for you:

Prompt for the three variables, and require that "e" be entered for the unknown. That's Euler's number, above the divide key. Then test for a value of "e" among the inputs, and calculate the result accordingly. Your code would then look something like this:

Input F, I, D
If F=e and I#e and D#e
Then Disp I^2 + 19.6*D
Else If etc, etc, Else Disp "Exactly one of F, I, D must be e."

The reasoning for using "e" rather than zero for the unknown is that conceivably one of the knowns could be zero.

--Richard

I can envisage a program so versatile most of the existing solutions would be deprecated.
Imagine if you could program an equation from a data booklet into a String variable, then have a program interpret it and ask you for each term. Whichever term you entered as "?" it would then rearrange the formula to find, and solve your equation for you.
Sure, it's a complicated process, but somehow I don't think it's beyond the capabilities of the device. I'd be willing to pay $20 if anyone actually codes it! As unlikely as I know that is to be.
Thanks!
Peter

I wouldn't mind getting ahold of a TI-89T or a Voyager 200 to write celestial mechanics programs in BASIC. On my computer, I've written programs to solve

1. The ephemeris problem. The geocentric position of a planet in spherical coordinates: R, right ascension, declination. The inputs? The orbital elements of the planet and a time.

2. The calculation of elliptical transfer orbits and the delta-vees for departure and arrival.

3. The calculation of hyperbolic transfer orbits and the delta-vees for departure and arrival.

4. The determination of a preliminary orbit (e.g., for an asteroid) from three angle-only observations - right ascension and declination - by the method of Gauss.

5. The prediction of eclipses.

6. The evolution of a planet/asteroid heliocentric position and velocity in the restricted two-body problem, with reasonably a small time step.

7. Many body problem for high accuracy check of Keplerian orbit solution, if practical - it is computationally intensive.

The thing is, I already have a computer, and it works just fine. GWBASIC, double precision, 1.8 Gigahertz CPU, all the RAM I want. I just think it might be fun to have these programs on a calculator, so I could carry it around with me.

Maybe I could afford one of the TI-89 Titanium or Voyager 200 that people are selling on eBay.

IF anyone could give me tips as to how to program stoichiometry on my Ti-83+ I'd be really grateful, I've made basic atempts yet my inexperience stalls me...I don't seem to get the good answer. If you have a detailed tutorial to do such a program plz send it to aild.tom.aild@gmail.com...thx!

what i actually need ids the codes...

So, I guess I'm the first...
I too would much prefer to talk about games than science...
however, I am in Honors high-school chem, and neaig that fine line between C and D..
So, wouldanybody get around to making a REAL periodic table, as an app or asm program? With atomic masses, valence numbers, things like that? I'd make it myself but all I know is BASIC...
However, I'm working on a prog to deal with gas-law problems

There are some quite good periodic tables to TI-86.

Just grab one of them, port it, and there you are!

If you don't know anthing about programming assembly, then ask someone to port it instead. Of course you have to ask the author before porting, but most people are just happy to see that people are intereseted in their programs.

And then you could also wait some months or so. I'm programming a new periodic table, with all the data in modules. I don't know when it's complete, but I will try to get it ported to the other TI-calcs too...

If you noticed on his profile it said he had a TI-83 Plus. And yes, I know you said he or someone else could port one. But (According to my knowledge) there are two foreseeable problems. The first is; isn't the 86 a 68k calc, and the 83+ is a .z80. I didn't think you could port to and from different... oh well. Also, Ahmed what's his name made a pretty good periodic table for the 83+, it has the atomic wieght, number, name, and something else... I forget. Oh well, look in the maybe Misc. programs and you should find one.

Gerhalt

P.S. Sorry if I was confusing!

Nope, TI-86 is also a z80 calc.

Porting between TI-83(+) and TI-86 is a piece of cake if you know both calcs fairly well.

But if there's already a good pericodic table out there there's no need to port one!

I once made a very good periodic table for my TI82 (in basic). It runs very fast and takes up a minimum of space (6-7000 bytes). The program should work on a TI82 as well as TI83. It is written in Norwegian, however it is translatable, let me know if anyone is interested.

dat0hsfb@stud.hitos.no

The e-mail address is old, you can now contact me under sgbware@yahoo.com.

There's a good periodic table application by Michael Vincent. It probably has more info than you'd need. The link above goes to its page on the site.

There's a good periodic table application for the 83+ by Michael Vincent. It probably has more info than you'd need. The link above goes to its page on the site.

There are many periodic tables floating around at my school. They are apps for the TI-83 Plus and I could E-Mail you one of them if you want to.

(validation might be a problem)

answer at onequestion06@yahoo.com

If you are working with a TI-89 there are a couple of good ones,
Basic:
Universal Periodic Table, is ok... but it's kind of slow.
Periodic Table, is a probubly the one that I use the most... it's fast, and works well.

ASM:
Period98 is well written, fast, and contains piles of information.

I knew someone that bought a TI83+ silver with about 5 different apps already programed in and one of them had a very sweet periodic table in it. It was obviously made by the programers at texas instruments and his calc is pretty new so try someone with that.

Or just use a paper table with the same or more data on it and not waste any calc space.

This is the BEST idea; anybody can do this (it is MUCH easier than it sounds in many aspects, and there are SO MANY WAYS you can do this, and SO MANY THINGS you can add)

THE POINT:
The idea is to make a PROGRAM that will read "BASIC" from a source file and convert into Assembly commands in a .z80 file (Tasm can compile it into a .8xp or something). The cool thing is that, since it's your program (or "our's", if anybody thinks we should get a bunch of people to help with how it will work), the code does not have to be in the EXACT format as on the calc; it can be however you want.

You could Also add extra features/commands that coudn't be done in z80 BASIC, but that could be done in ASM. However it's done (however simple), it can be in any format. It could be like a new programming languege or something that is nearly the same as (or better than) BASIC

It could start with the easy stuff like Disp, ClrHome, Input for Vars, Rom Calls, etc... and could have more complicated stuff added later. If anyone wants to take the idae far enough, then maybe I could see an actual Compiler thingy.

Exponding on this idea, a ASM Guru (not me, I just learned how to declare variables...) could create an application or asmprog that would create TI-8_ programs from ***C++*** or Java, i guess...

After all, don't most people who program calc's know C++? They did create high-level languages for a reason after all...

It is possible for simple commands like ClrHome and such, but you will need the parser to interpret more advanced commands, so that the speed won't increase much. This program won't have much use then