Re: Who uses a graphing calculator, and for what? Message #5 Posted by Crawl on 19 Apr 2012, 2:13 p.m., in response to message #1 by Peter Murphy (Livermore)
I have a feeling you don't know what use a graphing calculator has now. It's not just for graphing. But even if it was, it's much faster to set up a graph of a function (maybe not of experimental data) in a graphing calculator than it is in Excel.
Here's an example of when I used a graphing calculator for work when Excel faltered.
I had experimental values for the real and imaginary dielectric constant of a material as a function of wavelength and wanted to make a spreadsheet of its predicted transmission and reflection from that data.
This is possible, but
the equations are preposterously complex.
Nevertheless, I dutifully typed them in.
I did some sort of common sense sanity check of the spreadsheet, I can't remember what it was, but it wasn't working out. It just did not work. I looked over the equations but couldn't find a mistake (of course, they were extremely complicated).
So what I did was I loaded the data into my HP50, in CSV format, using an SD card. I derived the equations from first principles, using the 50g's CAS. It is almost impossible to make a mistake this way. The starting point for the derivation is not very complicated, particularly if you can use complex numbers (which the HP50g can, easily, but which Excel handles very awkwardly), so it's easy to key in. Then I ran the calculation, put it back in CSV format, back on the card, and loaded it back into Excel.
I was eventually able to find that I had indeed made some typos in the original Excel file, by comparing data to the calculator output.
I can imagine all sorts of criticism of this. "Why didn't you use another program on the computer?" Blah blah blah. Doing it the way I did was relatively cheap (even if I hadn't already owned the calculator), and was quick, easy, bullet proof and just about guaranteed to work, and, you know what, it was even fun, too.
There are definitely uses for graphing calculators today (though I prefer to think of them as CAS calculators -- I'll admit I have little use for, say, a TI83).
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