HP Prime: Home/CAS?


I think a lot of my difficulties with the HP Prime are due to the use of the Home and CAS views. The menus are the same in both, but some items (such as MAKELIST) seem only to work in Home view. Then there's the problem of defining a function (which must be done in CAS view) and plotting both it and its derivative. This requires a certain amount of juggling, since the Functions app, as I understand it, treats functions as numerical objects, and not as symbolic ones.

For example, I can define "f:= (x) -> (x^3-x^2)" in CAS, and to plot it, I can enter "F1(X) = f('X')" in the Functions list. But if I try to put a derivative (of either f or of F1) in F2, any of these happens: (1) I get an error "Error: Invalid Object", (2) the plot shows only the function and not the derivative, (3) the plot shows the derivative as the straight line y=0, (4) the calculator spontaneously reboots.

In fact, I find the Home/CAS view more annoying than useful, simply because moving things from one to the other is non-trivial. (If you define a function f(x) in CAS, then you have to type Shift-Alpha-F to obtain a lower-case f in Home view.) In my view a calculator, if it is to be used for education, should be as simple as possible, and Home/CAS seems to me to complicate things.

Am I alone in this, or has the rest of the world embraced this Home/CAS dichotomy?


You are not alone, I'm with you :-)
IMHO two things were done not the right way:

1) merge two logical different calculators in one physical case and
2) not documenting the resulting hassle


I'm totally with you. In my opinion the current concept of the HP Prime is ABSOLUTELY WRONG.

WE (practitioner, user, teachers, students) need no predefined variables or two views (Home, CAS). But the HP-ENGINEERS above us have different position.

In my opinion the problem is that the HP Prime is a HP39gii (or HP40gs or HP38g from 1995) adapted with XCAS from B. Parisse. And by mixing two systems beginns the trouble. Why haven't HP take the modern XCAS from B. Parisse (which have ALL required features: CAS, Spreadsheet, Graph-Apps, 2D-geometry and now attention: 3Dgeometry - and all CAST IN ONE POUR - on single source) and ported this sophisticated software on HP Prime hardware? And all would working just fine like clockwork.

So in my opinion XCAS should be the center, the heart of Prime. All other things should be adopted around them.

I have already tell this the HP-ENGINEERS, but i fall on deaf ears!

Sorry, for my very (very) bad english!


Well, bluesun08, you put your views with more vehemence and eloquence than mine, and I do agree. Rather than trying to be two different things at once (CAS and non-CAS), the calculator should have fully embraced xcas, and every aspect of it should have been built around that.




Man, this calculator is so frustrating to use.

But, I don't think is due the home/CAS design. The first *advanced* calculator I ever used had the same design, the CASIO Algebra FX2 (RUN/CAS) and it was very usable.

I remember my early days with my first HP, it was frustrating but not in this *cheap* way the prime OS feels. I don't know how to explain it, it is like the prime is constantly shouting "I DO NOT WANT YOUR INPUT; >ok but if I move this; NO!; >and with single quotes; NOO!; and prefixing thi-...; NOOOOO!".

I like the concepts and the hardware, but the software is so lacking: the reboots, the msgboxes, the flickering, all is adding up to a pile of annoyances where the truth is: the most you try to accept this device, the most you backtrack to your old hp or even a basic 4 function calculator app. We can just hope that it sells well to the students, and that gets poured into us with better next releases.


The HP Prime (software) design is unfortunate. But it is very unfortunate that HP decide to close their eyes to this fact.


But it is very unfortunate that HP decide to close their eyes to this fact.

It's been out for, how long, two months? And you already feel sure that HP won't address the problems?
I like this calculator. It has bugs, yes. It is different and needs to be re-learned, yes. So what? Do you want just another HP-41 with a few more bells and whistles? How many people do you think would buy a thing like that, besides a few dozen users of this forum?
They have to make a product that will sell. Not 1000 units, but hundreds of thousands or more. I already feel lucky that they left RPN in it (and I think more as a "gift" to us "aficionados" than anything else, since almost no one uses RPN anymore, face it). And so, I'm glad to have the Prime, with all its faults, and I'm confident they're working hard to improve it.

[/rant off]...

Edited: 24 Nov 2013, 11:36 a.m.


A solution that would satisfy me would be to actually make Home and CAS completely independent. From an educational point of View, CAS is more appropriate, specially if it is upgraded to a full implementation of Xcas. From the "hobby" point of view, Home should be upgraded to a full implementation of the HP50g, with RPL programming that allows stack manipulation. Besides all that, the Apps should include a 3D graphing like that in Mathematica(TM) (I believe that this is implemented in Xcas already).

Wishes ... it is that time of the year!

Edited: 24 Nov 2013, 2:11 p.m. after one or more responses were posted


Amen again. Hope for a better HP Prime II which concurs with the tenor of your approach.



Different persons, different point on view...
Some countries do not allow at ALL Cas in high school.
Some places, and persons want only numerical calculations (at some points)... at begining of high school, or in physics, you want numerical calculations for example...

One of the issue is that there is a vast customer base with various, sometimes incompatible needs/wants...

Prime tries to maximise the sum of all user hapinness :-)




I fully understand; even I alone have different goals for this machine. Thank you for your work.


Possibly Related Threads…
Thread Author Replies Views Last Post
  HP Prime: CAS taylor Alberto Candel 5 3,963 12-13-2013, 09:45 PM
Last Post: Alberto Candel
  HP Prime CAS curiosity bluesun08 11 4,788 12-10-2013, 01:03 PM
Last Post: Han
  [HP-Prime CAS] "Warning, ^ (Command) Is ambiguous on non square matrices"?? CompSystems 1 2,167 12-07-2013, 07:15 PM
Last Post: CompSystems
  HP Prime: complex numbers in CAS. Alberto Candel 1 1,887 12-06-2013, 02:36 PM
Last Post: parisse
  HP Prime: Proper Use of Home View and CAS View James Williams 9 4,234 12-05-2013, 02:44 PM
Last Post: James Williams
  [HP Prime] plotfunc() bug in CAS Chris Pem10 2 2,395 12-04-2013, 02:46 PM
Last Post: Chris Pem10
  HP Prime numerical precision in CAS and HOME Javier Goizueta 5 2,391 11-16-2013, 03:51 AM
Last Post: Paul Dale
  Need CAS help Michael de Estrada 6 2,614 11-13-2013, 01:29 AM
Last Post: cyrille de Brébisson
  HP Prime - CAS functions in Spreadsheet App CR Haeger 6 2,439 11-11-2013, 12:37 AM
Last Post: Michael de Estrada
  Another HP Prime CAS question Michael de Estrada 3 1,819 11-09-2013, 10:56 AM
Last Post: Michael de Estrada

Forum Jump: