Daughter's Initiation Into RPN

[TimT]

I took some courses a few years ago, and I got a kick out of the way some of the younger members of the class approached the problems...

The teacher would be writing the problem on the whiteboard... and they would be feverishly trying to input the problem into to the Ti-85 instead of just taking a few seconds and looking at the problem..

When the problem is on paper, its like a game..play with it do some substitutions..

and finally enter into the calculator..

A different way of learning now I suppose

[jyl]

Ok, I am playing w/ the HP48G emulator and have forgotten how to use it.

How do I generate a 3D wireframe plot? Say z = sin(x) + y^2. I go to PLOT, choose WIREFRAME, enter the right side of the equation, but can't enter more than one independent variable.

Help.

I know, lame.

[mjohnson]

Have you seen what some of those old HPs go for these days?

Even my 15yo 32S could be 4x what I paid for it.

The question is - sell or hold?

[fanaudical]

Personally, I think a 15-year-old HP is still better than any other calc you can buy on the market today...

[jyl]

I have a HP41 - I think a CV? Not sure. I bought it because it seemed cool, haven't gotten around to learning it. Sits in the desk drawer.

I never got into programming HP calcs. I did program my old TI59, back in the day (magnetic cards, etc). One of these days I want to learn how to program one of these HPs, and write myself a set of simple financial apps that will be useful for my work. None of the finance packages actually include the stuff I'd want.

But, as a practical matter, I could set up a template spreadsheet for my iPhone that would do everything I want, with a much better interface and without having to learn anything new.

Also have a few HP12Cs and a HP11C. Also a HP200LX and a a HP25C that no longer work.

For iPhone (and maybe Android) users who are HP calc fans, look into the various HP emulators. They are great, use the original ROMs in many cases, have photo-accurate interfaces, and cost $15 vs $XXX for a physical calculator.

[vash]

Originally Posted by jyl

Ok, I am playing w/ the HP48G emulator and have forgotten how to use it.

How do I generate a 3D wireframe plot? Say z = sin(x) + y^2. I go to PLOT, choose WIREFRAME, enter the right side of the equation, but can't enter more than one independent variable.

Help.

I know, lame.

X is the independent..and Y is the other independent (aka dependent) isnt it? damn..been a long time. i could barely plot y=x^2 now.

seems like these days, i use my HP to figure out my fuel mileage.

[masraum]

Originally Posted by vash

X is the independent..and Y is the other independent (aka dependent) isnt it? damn..been a long time. i could barely plot y=x^2 now.

seems like these days, i use my HP to figure out my fuel mileage.

y=X^2, easy, parabola, cup up...

I used to have a program in my 32S to figure mileage. I was in college and pretty much always had my backback with my calc with me. Anytime I got gas, I'd pull up the program, enter my current mileage and gas purchased and it would spit out my mileage.

[sammyg2]

Geez, my son just started 7th grade and blackberry I-pods are mandatory at that school, along with all sorts of programs and apps.

I member when we weren't allowed to use a calcumalator.

[vash]

Originally Posted by masraum

y=X^2, easy, parabola, cup up...

I used to have a program in my 32S to figure mileage. I was in college and pretty much always had my backback with my calc with me. Anytime I got gas, I'd pull up the program, enter my current mileage and gas purchased and it would spit out my mileage.

i programmed the Moody diagram into my HP. nobody could figure out how we cranked out calculations so fast without having to reference that stupid chart. the HP is one heck of a calculator. i have the periodic table of the elements in there..comes in handy in chemistry, trying to figure out those orbitals.

[masraum]

Originally Posted by vash

i have the periodic table of the elements in there..comes in handy in chemistry, trying to figure out those orbitals.

And how often are you figuring out orbitals these days?

Yeah, I like the HP calcs too. RPN is almost universally superior to algebraic. I've never had one of HP's really fancy $300 calcs. I had a roommate with one that used it primarily to play minesweeper. Hahah

[jyl]

Along one axis it would be a parabola, along the other it would be a sine wave, think a ruffle potato chip. I can't remember how to specify two independent variables.