HP 48GX and HP Prime - Converting Rectangular to Polar Complex Number (and vice versa)

[@theedspage]

R->C creates a complex number pair: (y stack_real, x stack_imag). 4 5 R->C returns (4,5) [4+5i] (MTH, NEXT, CMPL, R->C)

[@scottcollins7513]

Thanks, Edward -- that is something I did not know at the time of the video.

[@Chrls5]

Awesome!! Thanks!!

[@bolleke702]

Indeed, for immediately typing in the complex number with pi, you can also use the equation writer (on the 48GX)

[@bradbarton2930]

On the 48 GX, try drilling down to the Vector sub-menu and use the "E" soft key to convert the numbers in the first two levels of the stack to a vector. This makes building the complex pair much easier than editing the number and adding the 2nd dimension. Use MTH/Vector to get to this menu. You can also deconstruct a complex number by using the function on the "D" key. It obeys the polar/rectangular/degrees/radians settings that you've selected in the Modes menu. Thanks for the tips on using the complex modes on the Prime. I've never felt that this is well-implemented on the Prime, but maybe I'm just not used to it yet. I'll try your tips and see if I can get it to work for me.

[@scottcollins7513]

Great tip, Brad. Technically what you are suggesting is for vectors which may or may not suffice depending on whether you want to use the result in subsequent calculations -- regardless, your recommendation reminded me of a similar function in the Complex sub-menu (R>C = "D" soft key) that I should have used in the video.

[@2adamast]

As an alternative I see that when editing, after selecting edit the F key gives access to the stack and it allows to copy a stack value in line

[@Chrls5]

HP prime is a calculator designed for Schools and Universities, and the HP48 was designed for the field, for the real deal, and i actually find that the HP Prime is a bit confusing with everything prefabricated for you, so you have to keep in line a lot, whereas the HP48 you can mold the entire calculator to whichever discipline you are working in, that's what makes it so awesome to me :D if you asked me, i would keep the HP prime hardware, with the layout of the HP48, and the OS of the HP50g enhanced to work in the Prime Hardware. (Man, i think i'm more oldskool! hahahaha)

[@Chrls5]

Awesome!! i didn't know i could input complex numbers with space key, Thanks!

[@jesuisravi]

when I use the polar graphing app I can never get a graph--only a point--for instance if I input r=3cos(theta) I don't get a circle, just a tiny cross somewhere on the grid. What is the problem here?

[@scottcollins7513]

My best guess is that you need to go into settings and set "Angle Measure: Radians" -- if you have it set to "Degrees" it will not graph correctly.

[@jesuisravi]

@@scottcollins7513 Thanks. I will try that.

[@jesuisravi]

@@scottcollins7513 so, this morning I set the HP to work in radians and Lo! I started getting graphs in the polar app. I should have known that app would demand radians. Thanks again

[@scottcollins7513]

@@jesuisravi excellent! Glad to hear that worked. Thanks for letting me know.

[@reinlepiku445]

My HP Prime Software Version: 2.0.0.13865 (2018 08 02) Hardware Version: D CAS Version: 1.4.9 Serial Number: 9CJ020002C Operating System: V2.060.650 When I enter on the home screen (3,4) and press [ENTER], then 3 + 4 *i is displayed on both input and output

[@scottcollins7513]

There is a setting (under Home, not CAS) for "Complex:" -- you can set it to a+b*i or (a,b).