Calculator software

November 8, 2010 7:42 PM

Me: Poor student. Problem: The prices of TI calculators are 2 damn high. Looking for: Free software that performs wide range of operations (most important: a "matrix" function that is easy to punch in data).
posted by Taft to Education (34 answers total)

Wolfram alpha, excel, and openoffice come to mind.
posted by dfriedman at 7:43 PM on November 8, 2010

R?
posted by unknowncommand at 7:45 PM on November 8, 2010 [3 favorites]

Yeah, openoffice spreadsheet is free and will let you punch in data into a table and perform a wide range of operations on it. If you actually need to do "matrix operations" on your data, you should look at Octave - it's a freeware clone of Matlab.
posted by Salvor Hardin at 7:47 PM on November 8, 2010

Also, if a spreadsheet program does indeed float your boat, you can use Google Doc's spreadsheet without even installing anything.
posted by Salvor Hardin at 7:48 PM on November 8, 2010

Octave is the open source version of Matlab. They are both originally designed with matrix operations in mind, but can do much much more.
posted by trialex at 7:48 PM on November 8, 2010

Response by poster: Wolfram alpha, excel, and openoffice come to mind.

Any of those have comprehensive matrix functions?
posted by Taft at 7:48 PM on November 8, 2010

You may be interested in Octave, Scilab, or Sage. All of those will have comprehensive matrix functions.
posted by jedicus at 7:49 PM on November 8, 2010

I don't know what you mean by comprehensive matrix function. Here's info on Excel's MMULT function: http://techonthenet.com/excel/formulas/mmult.php
posted by dfriedman at 7:52 PM on November 8, 2010

Oh, there's another matrix function in Excel, MINVERSE.

A google search yields a lot of info on these matrix functions in Excel: http://www.google.com/search?q=excel+mmult+function&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a
posted by dfriedman at 7:56 PM on November 8, 2010

If I were you, I'd search Craiglist for an older TI-85. I picked one up for < 20 dollars and love it.
posted by jz at 7:57 PM on November 8, 2010 [2 favorites]

Can you be more specific as to exactly what functions you need? I could probably tell you exactly what Octave commands/syntax you need ...

It's been a long time since I used a TI calculator, but I'd guess that you could (more than) match its functionality with a combination of Wolfram Alpha (for more symbolic manipulation) and Octave (for matrix operations).
posted by Metasyntactic at 7:58 PM on November 8, 2010

Does your school have any licenses for computational software that students can use for free? I'm thinking Maple or Matlab.
posted by rancidchickn at 7:59 PM on November 8, 2010

Wolfram Alpha or the harder to use, but more complete Sage would be better for this in the long run, but if you're looking to just follow your teacher's instructions for a ti calculator, you could try using an emulator.
posted by martinX's bellbottoms at 8:02 PM on November 8, 2010

Best answer: R is free, open source and incredibly versatile. Yes, it can easily handle matrix operations and do so much more. There are thousands of contributed packages that can do pretty much any computation problem you throw at it.

Most of the stuff you need to do can be learned in a very short amount of time (examples of matrix operations in R). If you plan to continue in academia being able to code in R is a very attractive skill set to posses.

For more information on R, see this great Mefi post.
posted by special-k at 8:04 PM on November 8, 2010 [5 favorites]

Response by poster: Can you be more specific as to exactly what functions you need?

Finding determinants, inverses, holding several matrix variables like A=[1 2 3], B=[1 2 3] and performing calculations like A-1*B
posted by Taft at 8:06 PM on November 8, 2010

http://www.scipy.org/ is a free python based program that is equivalent to Matlab. Also, if you use a Mac there is a nice little program called grapher which plots functions.
posted by a womble is an active kind of sloth at 8:09 PM on November 8, 2010 [1 favorite]

Best answer: There are TI emulators; I can't find my TI89 currently, so I'm running an emulated version of it on my laptop via TiEmu.
posted by ubersturm at 8:17 PM on November 8, 2010 [1 favorite]

Response by poster: That'll work nicely, thanks!
posted by Taft at 8:22 PM on November 8, 2010

Response by poster: Also, I'll look into R.
posted by Taft at 8:22 PM on November 8, 2010

Nthing Maple and Matlab/Octave. I've used these programs do to specifically the things you want to do, and they work fine. If you're in university, your school should have licenses. If not, Octave is free and you can find the others online with a bit of digging.
posted by auto-correct at 8:24 PM on November 8, 2010

Wait are you a high school student? If so, consider this: when I was in school, they let us use our TI calculators on the SAT and math SAT, basically turning the tests into calculator tests and assuring you would net 700+ scores as long as you knew how to plug in the problems (yes, this actually requires some learning). Best 90 dollars I ever spent. I don't know if they have fixed this bug/feature in testing yet.
posted by tmthyrss at 8:33 PM on November 8, 2010

I'm a big fan of using the Python language with its Scipy/Numpy and Matplotlib modules, which ends up giving you something like the command line interface of Matlab. Couple that with Spyder, which is a GUI frontend, and you get something that's almost exactly like Matlab, but has the benefit of being in a real programming language that you can use with other stuff.

On preview, as a womble is an active kind of sloth said.
posted by malthas at 8:37 PM on November 8, 2010 [1 favorite]

To complete the calculator functionality, the best free graphing program I know of is Graph. It does symbolic calculus and makes pretty pictures.
posted by klausman at 8:39 PM on November 8, 2010

R or Matlab/Octave are well worth the effort to learn. R is more on the stats side, Matlab if simulation and numerical modelling is your bag.
posted by bonehead at 8:45 PM on November 8, 2010

Best answer: Actually, the exact syntax you used is a valid Octave command. Examples of what you asked for:

To assign matrix variables, just use
foo = [1,2,3]
bar = [1;2;3]
Foo is a row vector, bar is a column vector.
baz = bar*foo

To assign a matrix variable, use semicolons to separate the rows, commas (or spaces) to separate the columns
a = [1,2,3;2,3,4;3,4,5]
For inverse and determinant, use:
inv(a)
det(a)

If you need to know how to do anything else, just ask!
(good first place to look is to just type "help xxx" in the octave prompt)

I haven't used my TI-89 since I discovered Matlab/Octave freshman year of college. Way less kludgy of an interface, and way more powerful down the road.
posted by Metasyntactic at 8:46 PM on November 8, 2010 [2 favorites]

Being able to use the TI in class may be worth the cost. If you are a college kid, the marginal cost of a TI ahead of tuition and books vs the marginal benefit make it a no brainer.

If you are not a student, then go with R.
posted by everythings_interrelated at 8:46 PM on November 8, 2010 [1 favorite]

You're a student? Many universities have this kind of software available to their students, included in tuition. I used Mathematica as an undergrad. Matlab is another. Check your university's computing website for more information.

Then again, I've always gone to private school... my roommate from a UC says he had both Mathematica and Matlab.

If you don't have to use it in class, it'd be much more worthwhile for you to learn a computer language like Python. It does the job, AND you have the added bonus of putting "Experience with C/Python/FORTRAN/PICKYOURFAVOURITELANGUAGE" on your resume.
posted by chicago2penn at 8:58 PM on November 8, 2010

and by in class, i mean in the actual classroom -- like for a test, not just for homework.
posted by chicago2penn at 8:59 PM on November 8, 2010

When I was in college, student support services matched up people who were willing to lend their calculators for a term to students who couldn't afford to buy them. Maybe check with an office like that, if having the calculator in class would be sufficiently useful.
posted by bardophile at 9:21 PM on November 8, 2010

R is pretty good but being an emacs nerd I have to point out that emacs' calc package supports a surprisingly strong set of matrix operations. However, it's RPN so that may alter your brain in ways you don't want. I suppose that the emacs way though.
posted by chairface at 9:31 PM on November 8, 2010

Ebay, my friend -- I just saw one go last week for $15.
posted by liquado at 9:57 PM on November 8, 2010

Mathematical Visulization Toolkit might fit your needs.
posted by Confess, Fletch at 5:59 AM on November 9, 2010

I use Numpy/Scipy whenever I can get away with it. I have tried R for specific things in the past but never really got the hang of it.

Matlab knowledge is *critical* for many advanced classes at least at my university, and Octave is unfortunately not a great substitute yet (missing some important functions). I never actually bought a personal copy though.
posted by miyabo at 6:09 AM on November 9, 2010

I bombed my first statistics class because I cheaped out and tried an emulator instead of ponying up the money for a TI. I mean, I withdrew with plenty of time and the grade didn't count, but the teacher was teaching specifically to the TI and I couldn't keep up. Plus, with exams, you're not going to be able to use a laptop. Even the online parts of my class I just couldnt' get through. (My re-take of the class, I got an A.)

So I wasted $400 in tuition to not pay for a TI calculator I later got for like $35. Just keep that in mind.
posted by kpht at 6:40 AM on November 9, 2010 [1 favorite]