HP Prime Polar Mode

[lindsay1993]

I have never used an HP calculator before. I’m used to TI calculators.

On the HP Prime, how do you get it into Polar mode?

On my TI calculator I can set it for polar mode and then enter in 3 * I and it will give me 3 angle 90. On the HP Prime, how do I get it to do that? 

Lindsay

[Tim_Wessman]

Hello,

There is not really a "mode" for polar or rectangular. Rather, each complex number has carried along with it information about which form it is in.

You can type 3*i [ENTER]. Then you can toggle the form using the angle key (shift-multiply) and the lowest complex in the history toggles form. You could also select the complex in the history by tapping on it, and press the same SHIFT-MULTIPLY to toggle the form.

Alternatively, you can just type directly 3<angle>90 to enter a polar complex. This lets you do things like type 3i+2<angle>45

Doing it this way makes it so you can have various types of complex numbers at the same time without forcing them all into one form or another.

So to sum up, pressing the ANGLE function while a complex is selected will toggle its form, and typing the complex directly will keep the same form as what you input.

[lindsay1993]

Wow, that is so awesome. I love it much better than my TI-nspire CX.

Thanks for your help!

[dorbitbrown]

So, then, how does one construct a polar vector in programming mode?

HAngle:=1;

Local A,B,C;

C:=A∡B;  //Doesn't work

C:=[A,B];  //Doesn't work

C:=vector(A,B);  //Doesn't work

[dorbitbrown]

Correction to the previous post:

HAngle:=1;

Local A:=5, B:=45, C;

C:=A∡B;  //Doesn't work

C:=[A,B];  //Doesn't work

C:=vector(A,B);  //Doesn't work

[Maké]

Hi!, dorbitbrown: Welcome, to Forum !. Try learn, with this demonstration, in Spanish Language ... https://www.youtube.com/watch?v=13EZJyH8hPs

[dorbitbrown]

Maké-

Thank you for the tutorial.  However, my question relates to programming.  In other words, I am looking for something that works when programming in PPL.  I expected there would be something similar to use of the "∡" in Home.

From what I have been reading, It seems that there is nothing in PPL that will convert complex numbers between polar and rectangular.  There are the functions  polar_coordinates() and rectangular_coordinates() which return vectors.  This is not a very elegant solution, but it does help a bit.  Being used to programming the HP 25, HP35, and HP48g, I'm very surprised that HP would overlook this. Especially since the primary reason I purchased the Prime was for use in navigational problems requiring vector math in polar coordinates.

[Maké]

Hi!, dorbitbrown:

You can see ... http://m.youtube.com/watch?v=5krbLbQZEeo

[dorbitbrown]

Maké-

Thank you for the video in Spanish, implying that in PPL there is no native function or operator to enter a polar complex number, and using either of the following approaches to create complex numbers:

ZPolar:=EXPR(Magnitude+"∡"+Angle);
ZRectangular:=EXPR(Real+"+"+i*Imag);

Meanwhile, I've been doing some research, and found that the answer to my original question on how to construct a complex number in PPL is:

Z:=(A,B);

As far as I can tell, this approach always creates a rectangular coordinates complex number of the form A+Bi.

CONCLUSIONS

1. There is no simple way to key in  a polar coordinates complex number in PPL

2. To create a rectangular coordinates complex number in PPL, use the following syntax:

            ZRectangular:=(Real, Imaginary);  //Result is Real + i * Imaginary

3. Maké provided a workaround to create  a polar coordinates complex number:

            ZPolar:=EXPR(Magnitude+"∡"+Angle);

So, an implementation in PPL of a function to create polar complex numbers  is:

EXPORT ZPOL(Mag,Angl)

//Creates a complex number in polar coordinates
BEGIN
RETURN(EXPR(Mag+"∡"+Angl));
END;

Thanks,

Doug

[Tim_Wessman]

You *can* directly input polar complexes. I hadn't chimed in earlier because I assumed you were looking for 3 member objects which currently are not supported... (yeah, I know... hope to get this resolved before much longer 😕 )

To do a complex polar, just type (<num>, <angle><num>)   The angle symbol is on the shift multiply key.

That is [PAREN] [ 2 ] [ , ] [SHIFT] [ * ] [2] ENTER.  You can also type <NUM><angle><Num> also

To convert it back and forth between rect/polar complex, press the angle key again and it will toggle the lowest complex number in your history. Or select the complex in your histroy and press the angle key and it toggles the selected one. Below are four valid ways to enter complexes in alg/textbook mode.

(2,∡2)

5∡2   (note there is no space between the ang and numbers)

(2,2)

2+2i

Is perfectly valid input. If you'd like to see some built in help on this angle function, press the HELP button. Now press "keys" on the menu screen button, and then [SHIFT][MULTIPLY] for the Angle symbol.

Note that unlike older HP calculators, each individual complex will carry along with it the infor about whether to display in polar form, or rect form. Thus you can mix them in your history using the angle key to toggle the display for that specific item.