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The Future of RPN Calculators
Noksagt writes "HP's recent release of the 33s won't be the last RPN calculator. Former HPers at Hydrix are hyping an impressive Linux-based PDA/calculator, named Qonos. They have a survey up regarding features, etc. More information can be found at comp.sys.hp48 or The Museum of HP Calculators.
A new open hardware project called OpenRPN has also begun. Their mission is to produce horizontal and vertical format scientific RPN calcs and later a graphing calc."
maxima.sf.net is a truely awesome symbolic algebra program, it is derived from one of the first ever 'modern' computer algebra systems and was recently made open source.
If it could be put into a calculator, that would rock.
http://notanumber.net/
There's more details and pictures on hpcalc.
Quote:
Operating system:
eCos, running in 512KB SRAM and providing one month of battery life
Linux, running in 64MB of SDRAM and providing considerably more than a day of battery life
Other software:
Emulation of both the HP 49G and the TI-89
Advanced math software: Gnuplot, Giac/Xcas (supposedly better than Maple), MathsExplorer
PDA software: calendar, tasks, notes, time management
Datalogging capabilities
Processor:
Intel PXA 263 XScale processor, running at 400 MHz
32MB of on-chip flash memory
32-bit data bus
Display:
Grayscale 3" 320x240
Full support already exists for a color screen to be offered at a later date
Other hardware:
Mono speaker and microphone
Stereo audio input and ouput ports
Keyboard with tactile feedback designed for fast, accurate data entry
Compact Flash Type II slot
SDIO slot
IrDA port
USB client and host ports, supporting external keyboards, webcams, and other devices
Optional sled:
Vernier probe compatible
8 analog I/O channels
16 digital/sonic I/O channels
Extra high-capacity lithium ion battery
DB-9 serial port
Price:
Over US$350
WTF that isnt the chain rule.
d/dx f(g(x)) = f'(g(x)) * g'(x)
*cough*matlab*cough* erm, mathematica? maple?
Your Mom
Hoo-boy. I'm labeling myself as uber-geek.
The reason the 'r' comes and goes is because the 'Q', in Klingon, is sort of like an over done 'k' in English. It's pronounced toward the back of the mouth. The net effect is vaguely like a "kr" sound in English.
So "Kronos" is sort of a phonemic transcription of what "Qo'noS" would sound like.
-- I have monkeys in my pants.
Real geeks want an HP 16C replacement. My 16C's still going, and on only it's 3rd or so set of batteries since 1982. http://www.hpmuseum.org/hp16.htm
Here in the UK, they're forbidden in exams (up to and including university level) and frowned upon as a distraction and hindrance to being able to visual graphs yourself.
If you wanted to punch the same equation into a RPN calculator, you would need to break it up the same way. This is a pretty trivial example, but if you've used RPN (I haven't used it much at all) then I think you'll see what the parent meant.
P.S. - Real sophomores know how to spell it. ;)
[javac] 100 errors
That is the chain rule. Sheesh! Doesn't anyone know any mathematics these days. There's more than one type of notation for writing derivatives: f'(g(x))g'(x) is the same thing as df/dg dg/dx.
Doesn't it make you feel good to know that our freedoms are protected by politicans, lawyers and journalists.
Go sue your calculus teacher for malpractice. Seriously. I wrote THE EXACT SAME THING you wrote, but I used differential notation. You clearly haven't been taught differential notation. You likely wasted time memorizing formulas that should be instantly grokked (and are, with differential notation). I'd bet my next paycheck that you can't explain the purpose of the "dx" in an indefinite integral (and no, it's not to show that "x" is the independent variable in the expression being integrated).
Out of curiousity, did you use calculators in your calculus class?
For the keyboard.
THE NERD IS THE COMPUTER.
Second, you've committed the atrocious sin of mixing Leibniz notation with Newton prime notation. What a horrific mess you've created.
The proper way to write it would be:
h(x) = f(g(x))
h'(x) = f'(g(x))*g'(x)
I think this should help explain why the Leibniz notation is so popular, because in the Newtonian notation, a prime can only bind to a name, not an arbitrary algebraic expression. Hence you are required to introduce the additional function h(x) just to allow the notation to work.
Anyway, you're hardly qualified to school us in calculus.
Not to douse your fire, but I've been using grpn for a while, and it works quite well.
Reverse Polish notation was invented by an Australian in response to Polish notation, which was invented (gasp!) by a Pole.
The whole story here is
Except OpenRPN isn't trying to be a PDA. It has the hardware to do so (except that the first model will be a small horizontal format, a'la the HP Voyager (11c,12c,15c,16c) series. 1 or 2 lines makes for a difficult PDA. The open nature will likely let people put PDA features on it, but that isn't the goal of the project (though it is the goal of the quonos, which was also mentioned).
There are a bunch of others. My favorite is PARI-GP.
(S(SKK)(SKK))(S(SKK)(SKK))
That's why you should use variables on the HP48 for that kind of thing...
In school in electrical engineering, I had a huge set of formulas and constants stored in a directory on my HP48GX, all I had to do was to change a constant, then push the right formular onto the stack, press ->NUM once, and had my numeric result (even complex numbers) there, which would have taken at least two sheets of paper by hand.
Graphics are for the weak. Allow me to respond with my own shameless plug for Orpie; it runs in the console, the way God intended.
The prime is not limited to binding to names. In Newtonian notation this is expressed as
(f.g)'(x) = f'(g(x)).g'(x)
Just to pick a nit - IIRC, Newton used a dot notation, which this screen is too limited to display. Here's an attempt at explanation. If x were a function, then x with a dot over it would be the first derivative, and x with two dots over it(like an umlaut) would be the second derivative. I don't recall where the 'prime' notation came from.
It's not uncommon to use prime for spatial derivatives and reserve the dot for derivatives with respect to time.
Caunt isn't too bad. My copy originally belonged to my grandfather, then my mother. Its style is a bit archaic, though, as it was published early last century.
What a long, strange trip it's been.
For those with Linux searching for the most perfect RPN calculator, I have found it! Galculator, a free open-source GTK2 driven application fills the gap that is created by the absense of a HP calculator. I do hate that I own a TI-89 and not a nice new HP 49G+ due to extensive use of galculator I have come to love RPN during the conclusion of my high school junior year. So I say unto thee:
May your entity of lack thereof save RPN. (use galculator or if you use Debian, apt-get install galculator)
Karma: Good, or bust!