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+-- Forum: HP Calculators (and very old HP Computers) (/forum-3.html)
+--- Forum: HP Prime (/forum-5.html)
+--- Thread: Scientific Specific Units (/thread-5272.html)
Pages: 1 2
RE: Scientific Specific Units - luisphysics - 12-07-2015 01:21 AM
OMG the HP Prime calculator on Windows Store! When did this happen? I looked for it not long ago I feel and it was missing.
RE: Scientific Specific Units - chromos - 12-07-2015 06:15 AM
(12-06-2015 11:05 PM)Tim Wessman Wrote: For example, let's say that it were possible to give this choice:Why choose one item of the list? Make it all. You are the best calc company, who other could do it than you? :-)
1. Fix and make the unit conversion UI better then any prior calculator.
2. Make base conversions work even better then any prior calculator.
3. Make RPN work in the CAS.
4. Return 10MB of RAM to the end user for use in programs (giving you double what you have right now)
5. Implement a 3D grapher.
6. Fix the user keyboard.
Assume all these items take the same amount of time to implement. Which one is the correct choice? I suspect you might have a hard time deciding. I suspect whichever answer you pick might differ from mine, and probably differ from a large number of other people's choices.
RE: Scientific Specific Units - Dirk. - 12-07-2015 07:18 AM
... there is nothing wrong with the units-system of the prime. It is consistent. But introducing c² (MeV/c²) might cause trouble.
RE: Scientific Specific Units - hpfx - 12-07-2015 08:22 AM
(12-07-2015 12:53 AM)luisphysics Wrote: Maybe I should start a new Thread but what is wrong with the Units UI?The number of keystroke to enter assembled units, and with prefix...
every time you have to shift-unit...
converting can also enhanced regarding how we could convert with hp48...
RE: Scientific Specific Units - Tim Wessman - 12-07-2015 03:05 PM
(12-07-2015 07:18 AM)Dirk. Wrote: But introducing c² (MeV/c²) might cause trouble.Well, as a temporary improvement, I can very easily introduce the MeV/c^2 in a menu somewhere. For example, there is already "m/s^2" in the acceleration units. This isn't a "base" unit as it is made up of a unit from the length group, and a unit from the time group.
The problem is trying to keep it "grouped" as such without messing up lots of other things in different places. Most likely, it would only work automatically when using the "USIMPLIFY" command, and not perfectly even there.
So to the OP - where do you think that compound unit should reside inside the unit menu structure? MeV/c^2? Another one?
RE: Scientific Specific Units - Claudio L. - 12-07-2015 05:53 PM
(12-05-2015 07:07 PM)luisphysics Wrote: I notice a lot of people love the 50g. If I had to guess the reason HP didn't just upgrade the 50g hardware and roll over the software, was likely because the firmware/software/hardware are actually one fused unit.
The 50g isn't a fused software/hardware unit. It is nothing but an emulator running an even older platform. Now the emulated platform (Saturn) was very tightly integrated and "maxed-out".
Now regarding the specific unit you want... did know that the 50g has 'c' (speed of light) defined as a unit? So as long as your speed of light is defined as 1_c (as opposed to in m/s), any operation where you use the speed of light will not be numerically replaced, and your results will come out in MeV/c^2 directly.
So yes, the old maxed-out platform was very flexible and worked very well for physics and engineering. No wonder so many people still love it (me included). If you see it as a tool, then a fancy color screen doesn't beat "getting the job done".
RE: Scientific Specific Units - luisphysics - 12-07-2015 07:59 PM
(12-07-2015 03:05 PM)Tim Wessman Wrote: Well, as a temporary improvement, I can very easily introduce the MeV/c^2 in a menu somewhere. For example, there is already "m/s^2" in the acceleration units. This isn't a "base" unit as it is made up of a unit from the length group, and a unit from the time group.
The problem is trying to keep it "grouped" as such without messing up lots of other things in different places. Most likely, it would only work automatically when using the "USIMPLIFY" command, and not perfectly even there.
So to the OP - where do you think that compound unit should reside inside the unit menu structure? MeV/c^2? Another one?
So please
Well I would not rush and put in anything until the it is sorted out.
Distinction between a Constant with or without units.
One issue I see is how the constants are structured. Because in reality they are not constants. They have units. There are only a few REAL Constants without units. One example is alpha = 1/137. That has no units and you portray it correctly in the Constants menu.
Here is another issue that as an implementer have to decide is fixable. When I click on say hbar. I get a number. Why can't it stay as a variable? And only when you evaluate by pressing enter does it do its parsing and spit out the answer. The end user doesn't need to see the number when doing the calculation, it can be previewed in the units menu.
One thing that might fix this is to call hbar a unit and name it _hbar where hbar is the character. Of course this means that it is a symbolic calculation. But canceling out units is symbolic. Sure it is nice to do units in the home menu, but it is a CAS feature.
So is it possible and logical to distinguish between unit-[/code]less constants like \pi and planks constant which has units?
RE: Scientific Specific Units - Dirk. - 12-08-2015 07:16 AM
Hi,
to answer Tim's question where the unit MeV/c² should go:
MeV/c² has the dimension of a mass (E=mc²). It has to go to the Units->Mass-menu, since MeV is already in the Energy-menu. Anything else would be inconsistent.
c is already in the physical constants.
The prime behaves correctly:
Enter 0.511MeV (i.e. the rest-mass o the electron), divide it by c*c taken together with its unit _m/s from the built in constants:
0.511_MeV
--------------------. You get some Number in the unit MeV*s²/m²
299..._m/s*299...m/s
Use CONVERT (strange number with its strange unit, 1_kg) and you get 9,109..E-31_kg. You can check the result using the CONSTANTS->PHYSICS->me.
Everything is working nicely.
RE: Scientific Specific Units - Dirk. - 12-08-2015 08:27 AM
A bit off topic, but since Tim gave some insights into priorities in prime development:
I do think the prime is a very good calculator with a very bad reputation and a very low visibility. Look at the reviews in german amazon and you will understand.
About visibility/marketing:
At my university (somewhere in germany, ~30000 Students) they educate future math teachers. These students get a TI nspire CAS. Do they use it? The one I asked (bad statistics, I know) did like it and found it very useful. But he had a second calculator (some CASIO) on the desk to do quick calculations - to get the work done.
Lessons to learn?
1. HP has to target teachers education at universities. (Provide a lot of good materials for teachers, go to the didactics professors at university and show what you have. Teach them: Using HP you students will not learn a calculator, but how to solve mathematical/physics problems.
2. Improve your manual. (With regard to contents AND make it easy to print on normal paper - form follows function!)
3. Always look at the user interface: The quickest way, even for the tiniest calculation, is using a HP.
... hope I did not overstep a border with this comment.
This brings me back to User-Keys/User defined functions and interface.
1) It would be nice to have direct actions happening when starting a user-defined function without the necessity of pressing ENTER later on. It would allow for things like DEG-to-RAD /RAD-to-DEG with a single keypress or convert 0.001 to 1E-3 with a single keypress... "The quickest way is using your HP".
2) Improve RPN and allow programs interacting with the stack. RPN is something only HP provides. (Go to the computer-science didactics professor :-)). This might shut-up all the RPN fans and help to get nice reviews on Amazon. Look at the very nice youtube-videos of rolinychupetin on the 50g. Look how he defines a user key for impedances in parallel. Look how he uses it. Impressing - "The quickest way is using your HP".
RE: Scientific Specific Units - debrouxl - 12-08-2015 10:16 PM
Quote:There are plenty of good signs that overall Prime is moving in a good direction, and being well received generally. I mean, just recently THE MAJOR TI USER SITE IN EUROPE (tiplanet.org) placed the HP Prime as tied for top choice for the calculator to purchase! (It would have been #1 except for a problem with battery life when testing for an exam starting requirement in 2017). I don't think anyone would have seen that recommendation coming just 2 years back...TI-Planet admin here, though I didn't participate in the writing of this particular article. Thanks for the mention
Yeah, the Prime is a good choice for French high school students, in terms of functionality. What's more, given that nowadays, most bugs or limitations don't affect most high school students (the first index in a series used to be locked at 1 on old firmware versions, but it became configurable to e.g. 0, more usual in French classes), the Prime simply deserves one of the two top spots in last year's ranking - we'd be unfair otherwise
The Prime usually has better battery life than the Nspire CX (CAS)... except for that strange quirk in exam mode.
RE: Scientific Specific Units - d b - 12-09-2015 03:07 AM
(12-05-2015 09:23 AM)towe Wrote: I'm pretty sure we won't see another update for the Prime.
I believe I heard at the last HHC that HP has been doing updates on the Prime about once every 6 months. I don't know, but I'd guess they'll slow down on that before they stop altogether.