I need a graphing calculator, TI or HP?

I’m taking a robotics class for the next few months, and it requires a graphing calculator. Specifically “A calculator (preferably one that displays formula history, like a TI-83 or TI-89)”. I’ve never used one before (not stupid, just old). I thought I would tap into the collective Doper wisdom and see who likes particular calculators, and why.

For years, my go-to calculator has been a HP-15C I got in college. I do like the RPN notation. (Seemed weird when I first read about it, and then a godsend after I got used to it.) Is that even still an issue with graphing calculators?

It seems to be a choice between Texas Instruments and Hewlett Packard. Does anybody have a strong preference one way or the other, and what others factors should I consider besides the entry mode?

I have the HP50, it’s excellent, but it is probably best for you to go with the TI. They are more common, so more people will be able to help you when you have trouble.

I especially love programming the HP in RPL. You just do the calculation steps as normal in RPN, and then you can save the result as a program.

I’m not anticipating having any trouble.

But it may not be my decision to make; the class starts on Tuesday and I’m not sure if there’s any store around here that would have the HP in stock. I’ll check the MIT bookstore; if it’s not there, it’s probably not anywhere.

In my experience, college textbooks will often tell you which buttons to push, IF you have the right calculator - so if they say “TI” I’d go with a TI just in case.

The TI-89 was a fantastic calculator; that’s all I know. If you get a TI, don’t bother with TI-83 or any other such far lesser things.

Of course, the world moves on; the phone in your pocket is likely a far more powerful computing device than any of those were. I’m surprised there isn’t quality graphing and symbolic calculator software freely available for computers, cellphones, etc., by now.

Almost all serious work in robotics and allied disciplines these days is done in Matlab, so it’s a little interesting that your class is requiring something as archaic as a graphing calculator. Is it a large undergraduate class that requires in-class exams? That’s the only reasonable circumstance I can think of. I had a TI-89 back in college that kept me happy, so I guess I’ll vote for that.

Between Octave and R, you’ve got the graphing and numerical computing pretty well covered. There is a symbolic computation package for Octave, but I’ve never used it, so I can’t say anything about how well it works.

I don’t have a smart phone, yet. I’ll take the plunge one of these days.

It’s not a college class. There’s a local place (don’t know if it’s a company or a co-op or what, exactly) that has space and equipment for artists for a monthly fee. Not everybody needs their own welding and machine shop. And they offer classes. I took the introductory electronics class last fall and learned a lot. This is a three-month class and we’ll be building two robots to be used there in the future; a wandering vending machine and an industrial-sized Roomba.

I am considering a career change. I’ll see how the class goes.

I like to use Maxima for symbolic math; combined with Imaxima and, of course, Emacs it gives you a great symbolic algebra system with a pleasant UI.