Graphing Calculator With CAS, HP or TI? - Page 1
Forum section: electronics / general

author: labarowski
author_rank: Contributor
timestamp: September 28, 2012, 10:53:06 pm
content: I'm a third year ECE student and I'm planning on upgrading my TI-84. I've been throwing around the possibility of buying a CAS calculator for a while, but I'm taking a semiconductor physics course right now which covers quantum mechanics. My TI-84 often rounds some of the ridiculously small numbers to 0, while my teacher's basic HP scientific does just fine, so this seems like a good time to pull the trigger and upgrade. I'm leaning towards the HP 50G. I've used RPN with xcalc on my pc and this is definitely a great feature. I would like to know how the CAS system on the 50G stakes up with the similarly priced TI-89 Titanium or a member of the Nspire family. A friend with an Nspire was saying that there is an option to show step-by-step solutions of calculus functions in the CAS. He also said he had never personally used the feature, so maybe someone can confirm this? I've also heard that the screen resolution is somewhat low on the 50G. All other things being equal, I would go with the 50G for RPN, but I wanted to get some opinions here first. I downloaded an emulator for the 50G, but I'm not sure if such a thing exists for the TI calcs. Anyone know if there is a TI-89 Titanium or Nspire emulator? Would be nice to try them all out first.

author: T4P
author_rank: Super Contributor
timestamp: September 29, 2012, 01:41:32 am
content: TI-89 Titanium yes, TI Nspire not. But that's on Android Not PC

author: IanB
author_rank: Super Contributor
timestamp: September 29, 2012, 01:51:20 am
content: The only purpose for calculators these days is to help you take exams and tests. Either college exams, or later on tests like the EIT or PE exams. So mainly, you'd want to check what calculators are permitted in those exams (hint: not the HP 50G).If you want to buy a calculator like the HP 50G, you can choose based on its value to you as an entertaining toy. It doesn't have an actual professional use. In the real world, you will use Excel for basic calculations and Matlab or Mathematica, or dedicated simulation tools like LTspice, for advanced calculations and algebra. The only kind of pocket calculator you need in 2012 is a basic $20 scientific for those odd occasions when you don't have a computer handy--and even then your smart phone will have a better calculator built in.

author: labarowski
author_rank: Contributor
timestamp: September 29, 2012, 02:48:32 am
content: Thanks for the honesty guys. That's definitely not the answer I was expecting based on what I've read elsewhere. Still, I feel like the $100-$150 that I would spend on a calculator with a CAS is a fairly small investment in the long run. That's around 5-6 months of a mandatory smartphone dataplan. Although I suppose I could get an itouch or android mp3 play for around twice the price, which would be easier to justify than a smartphone/contract. I'm not really even sure what a Mathematica/MatLab license will cost. I can supposedly get both free from my university now. I've actually been using MatLab to do my physics of semiconductors homework to avoid the round to 0 issue. On tests I just keep track of decimal places manually and add them at the end. Both are a bit more tedious than just plugging it into the calculator IMO, but I'm not complaining. Mathematica looks promising but I haven't figured out how to get a license from my university yet. Anyway, I just spent over $500 for books for this semester (keep in mind I got all but one of them used), so another $150 doesn't seem too bad if it will be useful later on. Having said that, I'm not set on buying a CAS calculator. I've got the 50G emulator running and I'll see how I like it. For the sake of argument though, I would like to know which of these calculators people think are best. I'm sure there are other people who will stumble across this thread as well. I certainly have looked at quite a few 50G vs 89 threads - I'm just trying to target EEs by posting here.It looks like I can't even use the TI-84 on the EIT/PE exams. These are really the only standardized tests that I have left, although some teachers have a no CAS policy.

author: robrenz
author_rank: Super Contributor
timestamp: September 29, 2012, 02:52:46 am
content: A student license of Maple is about $125.00 Way better than any calculator.

author: IanB
author_rank: Super Contributor
timestamp: September 29, 2012, 03:54:07 am
content: Ah, when I said Mathematica I probably meant Maple. Thanks for mentioning that.The truth is that when you are at work you won't have to pay for those licenses, the company will provide the software tools you need.Computer algebra systems can sometimes help with tedious work, but as a student isn't it better to learn how to do it on paper? It acts as a workout for your brain, like going to the gym.I'm honestly serious when I tell you that as a professional engineer I haven't used a pocket calculator in decades. Every calculation I need to do is more conveniently performed on a computer screen. It allows me to edit and save and re-use the calculations, to print them out if needed, and to email them around when communication and collaboration is needed. A pocket calculator is hopeless for that, even if the most advanced ones should happen to have a USB interface.

author: amvakar
author_rank: Contributor
timestamp: September 29, 2012, 04:15:36 am
content: I learned to program efficiently by hacking various functionality into the TI-84, including arbitrary-precision arithmetic without the rounding errors. But I just can't justify treating it as anything more than a programming challenge anymore. If I'm too lazy to do basic maths, my phone has Wolfram Alpha. If I'm doing anything serious, there's no reason to leave the multi-gigahertz machine with multiple cores to playing background music and turn to the microcontroller for help. The only times I use a calculator are during exams and when I'm working on something that has to be above napkin standards but isn't worth the time of grabbing a laptop.It should also be noted that there is nothing more unpleasant than hunting down AAA batteries five minutes before an exam. That experience was enough to get me to go for a simpler design; the eventuality of the EIT/PE helped decide which one.

author: bingo600
author_rank: Super Contributor
timestamp: September 29, 2012, 12:29:38 pm
content: If you have the 50G emu , just install the TI-89 emu and compare themhttp://forums.afterdawn.com/thread_view.cfm/358142http://lpg.ticalc.org/prj_tiemu/I just installed the TI-89 on Linux.Btw: I have bought the HP-50G , the TI-89I , and lastly the TI Nspire CX CAS.The TI-89I was for the daugthers highschool (i bought it 2 years ago), but the school changed track this year to the Nspire , so i had to get one of those instead.TI (teacher programmes) apparently affects the contents of the math lessons , and the teacher insisted that the students buys the 1'year PC-Nspire licence (each year). As the lessons contains examples made for that calculator.But looking at TI's homepage i found out that buying the Physical Nspire included a non-timelimited PC-Nspire also , at +25% of 3 x 1'years licences.So basically i got the PC-Program and the Physical calc for 25% extra.I keep the 50G for my self , and i like it better than the TI89.Even though i have it set for Non-RPN.I'm an old TI fan , and have always had TI's before , since i got my TI-59 back in 79'But i do like the HP50G better than the TI-89I , the TI-89 seems slower and a bit out of date.I haven't tried the Nspire much , but it might be able to convert me back to TI.The Nspire is a nice calculator , It's fast and i like the color display , and you can program it via the LUA languageBut i'd check it's capabilities , for engineering before getting a Nspire.And make sure it can do the same or more than the TI-89 , i can't really decide if i think the Nspire is more of a Highschool calculator with a "Geek touch .. The color screen"Edit: Ohh and i think i saw the Nspire CX CAS , was also forbidden in some US tests/exams , the non CAS was allowed i seem to remember.ams/Bingo

author: h2o
author_rank: Newbie
timestamp: September 29, 2012, 06:06:33 pm
content: I'd get the hp. I haven't used the 50, but the 48 was a wonderful tool. Obviously no one should ever use a calculator. Do it in your head. However, if you happen to need to use a calc, HPs are great. RPN is a real time saver. Do be swayed by the haters. I get $$ to program excel, but I love an HP. The calculator can fit on a desk or in a drawer and just works. Less distractions and I don't think a phone will ever replace the nice tactile feed back for me. Now in 2112, maybe there will be a better neural interface. Computer programs have their place, and are superior for many things. They aren't substitutes. Once you go RPN, you won't go back.

author: labarowski
author_rank: Contributor
timestamp: September 29, 2012, 06:39:21 pm
content: Thanks for the input guys.IanB, for the record, the CAS is just a selling point. Because these calcs are so closely matched though, it is a deciding factor. I agree that in general it is much better to do math by hand. I have friends who graph functions and find the intercepts rather than do basic algebra by hand. It's ridiculous and good luck finding imaginary answers like that. There are definitely some instances on exams that allow a CAS where I might use it to check answers or save time though. I definitely feel like a CAS calculator would promote laziness less than Mathematica or Maple though.amvakar, any chance that you released the arbitrary precision arithmetic function? That is, after all, one of the reasons that I am considering ditching the 84. You bring up a good point with the EIT/PE exam too. My teachers HP scientific doesn't have rounding errors, so maybe I should go that route. I could probably borrow a calculator for those exams though.h2o, all other things being equal, RPN is the deciding factor. I definitely like RPN based on previous experience. I am reading that you can add RPN to the 89 though.bingo600, exactly the models I'm looking at. I will definitely check out the 89 emu. Guess the only way to get an NSpire emu is to buy TI's software. The new NSpire definitely packs a lot of features - it looks a bit awkward to carry around and use for day to day stuff though.

author: amvakar
author_rank: Contributor
timestamp: September 29, 2012, 09:08:31 pm
content: In order for it to have been worth releasing, it would have been necessary to risk bricking the calculator with the improved math functions baked into the firmware. As acquainted with TI's code that I became during high school, I was not willing to go that far.As far as borrowing calculators for exams, I've never liked doing so, but that's because I've grown to like RPN far too much after using an HP.

author: nanofrog
author_rank: Super Contributor
timestamp: September 29, 2012, 10:51:51 pm
content: I own a 50g, and prefer it to the TI89 (not had access to an Nspire), and RPN to CAS. I like the tactile feel and dedicated function keys of a calculator when needed or is more convenient than a computer.

author: Someone
author_rank: Super Contributor
timestamp: September 30, 2012, 02:09:07 am
content: Quote from: labarowski on September 28, 2012, 10:53:06 pmDo you have some examples of the computations that are rounding out? The legacy TI computational system is a floating point decimal based design with a silly huge range of exponent.Quote from: IanB on September 29, 2012, 03:54:07 amIts this sort of using a massively excessive tool for the job that those software companies live on, the costs of providing matlab seats is huge and many smaller companies do without it. While the free alternatives are good and largely replace matlab for anything other than physical interfacing they're still only numerical computational systems (more on that later).All the jokes around about the cost of high end calculators is rather moot when you look at what equivalent software costs.Quote from: IanB on September 29, 2012, 03:54:07 amCalculators survive because of their optimised user interface, otherwise they'd all have turned into blocky touch only devices by now. Once you are well practised in a specific calculators use its much faster than computer based alternatives, and they dont have a UI refresh every second year that gets in the way of the workflow and you have to relearn.One Calculator/Software package is not enough!Trying to use a symbolic system for numeric analysis and vice versa ends up being much more complicated than needed. Just as anyone using software would have a good grasp of both techniques, the associated software, and when to apply them, trying to shoehorn a symbolic calculator into numerical engineering work is painful.I have a TI-86 that is used almost daily in my professional work with a huge multinational engineering company, but its one tool among many. On the occasion that I need symbolic solving I have a Nspire CAS, its sole use for me is symbolic calculus and I've pushed a fair few problems into it that arent solvable. While we have matlab seats floating for use there is no symbolic tool licensed for us, even big business wont provide anything you want.

author: robrenz
author_rank: Super Contributor
timestamp: September 30, 2012, 02:35:02 am
content: Quote from: Someone on September 30, 2012, 02:09:07 amNot with Maple. That is the beauty of Maple compared to the others It work in both realms seamlessly

author: Someone
author_rank: Super Contributor
timestamp: September 30, 2012, 02:57:11 am
content: Quote from: robrenz on September 30, 2012, 02:35:02 amAs with most software packages its always growing, but maple as an example is missing a lot of classical computational things such as the meagre statistical analysis included (and really, when it gets big there are dedicated packages for that). Even a mid-high end handheld calculator offers easier to use and more powerful statistics than maple. A few other missing computational things without looking too hard are the lack of rounding modes and fixed point support. There is no one tool to rule them all.

author: labarowski
author_rank: Contributor
timestamp: September 30, 2012, 03:42:41 am
content: Quote from: Someone on September 30, 2012, 02:09:07 amThis is the equation that I'm referring to- although my textbook actually gives the equation with plank's constant^3 and has only (2m)^(3/2) <(this is why I like the idea of RPN.) This is a key difference. Using plank's in Joules (6.625x10^-34 J-s) to the third power, my TI-84 running 2.55MP (updated. not from factory) will round to 0. It will handle plank's to the power of 2 just fine, so it looks like I should just use wikipedia's equation. We also are dealing with a set volume too. Volume of a sphere I believe.Quote from: Someone on September 29, 2012, 03:54:07 amWould you say that the HP50G is lacking in the CAS department then? I thought that it had a fair amount of calculus functionality...

author: IanB
author_rank: Super Contributor
timestamp: September 30, 2012, 03:52:00 am
content: Quote from: labarowski on September 30, 2012, 03:42:41 amI didn't make the quote above--perhaps you would correct the attribution?

author: IanB
author_rank: Super Contributor
timestamp: September 30, 2012, 03:58:21 am
content: Quote from: labarowski on September 30, 2012, 03:42:41 amI'm sorry to tell you, but that is not a problem with the calculator it is user error. What you describe is not "rounding error" but a problem with scaling. You need to evaluate the formula in a proper order to retain reasonable scaling of the intermediate results. If you were evaluating that equation using a slide rule in the 1950's you would have had no problem--the issue is that you are being misled by an over reliance on the calculator rather than gaining an understanding what it is you are evaluating.

author: labarowski
author_rank: Contributor
timestamp: September 30, 2012, 04:21:54 am
content: IanB, sorry about mis-crediting the quote. It is corrected now. And yes, you are somewhat right. I used the equation as it was given in my textboook while simply pulling the ^3 outside the ratio would solve the issue (as it is in wikipedia's equation). As I said before though, I've just been keeping track of the power manually and adding it in after the fact up until now - so its not like I'm incapable of doing the problem without an electronic mind, I'd just rather have the equations work as they are given on a midterm or final. Anyway, this class is not the reason I'm thinking about another calculator, its just got me considering it again.EDIT: Actually, based on what little I know about slide rules, I don't think that they (in general) could handle a power like -34, which would leave me handling the powers separately and adding them in at the end - which is exactly what I've been doing. That being said, your point is by all means valid - I don't want to use a calculator as a crutch. But if I'm honest, I'm not above over-using my calculator on a test. Regardless of my skill level, I'll always be more confident in the calculator's ability to do basic arithmetic than my own.EDIT2: Actually, it looks like it wasn't uncommon for for slide rules to have scales up to 1000 power - but I am now fully convinced that it was always easier and less time consuming to do basic arithmetic by hand than use one of these. Also, it sounds like accuracy was never guaranteed with large arbitrary powers. I am quickly diverging from the topic though.

author: IanB
author_rank: Super Contributor
timestamp: September 30, 2012, 05:13:40 am
content: What was saying about slide rules is that a floating point number like 6.625x10^-34 is really the number 6.625 with the decimal point moved 34 places to the left. When you worked with a slide rule you just took the number as 663 in your multiplication or division and worked out where the decimal point went afterwards--just like you were saying about keeping track of the exponent manually.That said, the equation you referred to does have some pretty ugly scaling and getting decimal exponents over +99 or below -99 can certainly upset many calculators. It's nice if you can just let the calculator handle the arithmetic but apparently on occasions like this you may have to pre-order the calculation to avoid overflow or underflow. That's life in the world of physics I guess.

author: labarowski
author_rank: Contributor
timestamp: September 30, 2012, 06:05:12 am
content: Cool, well at least we are on the same page then and I got to learn a thing or two about the history of early calculators.

author: Someone
author_rank: Super Contributor
timestamp: September 30, 2012, 07:03:38 am
content: Quote from: IanB on September 30, 2012, 05:13:40 amLooks like you have it spot on, TI-83 descendants have inherited its 8 bit signed exponent as this must have been deemed adequate for high school math problems, where as the high end TI-86 and TI-89 have a signed 3 decimal digit exponent.Quote from: labarowski on September 30, 2012, 03:42:41 amI cant comment on its peculiarities as I havent used one, they are held in high regard but the best judge of whats good for you is you. Try and test drive one before purchasing.

author: h2o
author_rank: Newbie
timestamp: October 01, 2012, 10:27:47 pm
content: Quote from: labarowski on September 30, 2012, 04:21:54 amNo!You can always do basic arithmetic better & faster than a calc, if you want/try. Have faith.

author: olsenn
author_rank: Frequent Contributor
timestamp: October 01, 2012, 11:00:40 pm
content: Trust me; TI makes FAR better calculators than HP! I own a TI-86 (which I've used heavily for over a decade) and a TI-nspire CX CAS (fairly new) by TI, and a HP-50g and a HP-12C by HP. I have used many other calculators by both companies as well.The HP calculators are build cheaply and they will not last (the buttons have already begun to stick in my HP50g, and I've also lost a line on the display from one small drop). Texas Instruments calculators on the other hand, are build to last a lifetime! I've droped my TI-86 countless times and it still works just like new. I hardly ever use the HP-12C, so I can't really comment on the durability of that, but it looks and feels cheap also. As a side note though; I think the 48-series of HP calculators, prior to the 49 (and 50g) was released are MUCH better quality; but still not as good as TI.The battery life of the HP-50g is abysmal. My TI-86 lasts years of intensive use, but my 50g only gets a few months. One point a will make though, is to go for the TI-89 or the regular nspire CAS model, as opposed to the nspire CX CAS -- the latter uses a rechargable battery; it's meant for high schools (which is where all their money comes from with graphing calculators), and if you're putting it in a charging cradle, it is great. However, give it a full charge and go to use it a month later, and it's dead! There's really no need for a colour display on a calculator anyways!Lastly, the HP 50g is MUCH more difficult to learn than the TI-89, but you can work more quickly with it after you've spent a long time getting used to how to use it. However, the nspire series of calculators are not only even easier to learn than the TI-89, but you can do your work far more quickly than even the most skilled 50g user can! In short, RPN is better than standard type, but textbook style entry on the nspire beats the hell out of RPN any day.

author: FenderBender
author_rank: Super Contributor
timestamp: October 02, 2012, 12:10:02 am
content: My school loans us Ti-89s for our calculus course. It's a very nice calculator. Has all the functions you could ask for. As far as an EE calculator, it's relatively useless. If I'm actually designing something electronics-wise I use my Sharp EL-W16X. It has some actually useful features including a Decimal <> Binary/Hex etc. converter, an engineering mode that can use prefixes like nano, pico, kilo, etc and it's not too jumbled like the Ti-89. I believe it also has some sort of solver feature, but I've never used it.

author: h2o
author_rank: Newbie
timestamp: October 02, 2012, 01:27:21 am
content: Quote from: olsenn on October 01, 2012, 11:00:40 pmThe TIs may be more physically robust. Have a handful of TI-8Xs, they don't really seem to break. The HPs may not be as rugged; they don't handle drops which does suck. I think a used 48 would cost more than $140 on ebay. However for actually using a calculator to calculate, there's no comparison. Maybe I would rather use a computer than a TI. You really can't beat the HP. I'm not sure about the 50, but the 48 has around 100 lines of scrollable input. Combined w/ RPN, this makes long calculations incredibly easy and simple to review/check. Also it is probably one of the best calculators for physics. I don't think you can work any faster than RPN on an HP. That may be why it's the basis for Post Script....So if you can make a case/skin for your HP, it may handle rougher handling, but still you should get 5 or 6 years with avg. bumps/low drops on carpet. The TI is less useful IMO opinion. I would trade 20 TIs for 1 HP... well actually I wouldn't unless I sold them and then bought another HP.

author: Lawsen
author_rank: Frequent Contributor
timestamp: October 16, 2012, 07:24:04 am
content: They are all good. I have an old TI Nspire CAS and even the student version non CAS with the two detach able keyboards as Nspire or TI-84 Silver edition keyboard. If you like color than you will need a TI Nspire CAS CX or Casio fx-10CG in North America and same machine, but different number in Europe, the Casio fx-20CG. The Casio color takes some getting used to of accessing the pi functions and unit conversion, not very intuitive as the TI Nspire. I have not tried the TI Nspire CX, color. The HP-50G are good, too. I have the earlier HP with defective keys. The TI-84 Silver Edition has a really nice built in software like periodic table and most of the physical constants and handy software. If you like RPN, reverse Polish notation, then HP Kinpo of main land China is the way to go with all of its defects and quibbles, but no color, yet. HP Kinpo is behind in calculators, no color model, while Casio and TI have color models. TI Nspire CAS CX uses a recharge able battery for the color model. I am sure you already know about Androids, Apple I Pads, and Math Lab, Maple, and Mathematica software. There are HP 10C, 11C, and 15C replicas made by a Swiss shop.

author: olsenn
author_rank: Frequent Contributor
timestamp: December 27, 2013, 04:07:19 am
content: My HP Prime calculator just arrived! So far, my opinion of it is that this calculator is the most powerful calculator ever made; however, it also has several unforgivable flaws:Pros:* (Very) Powerful CPU. Extremely fast* Beautiful, high-res, colour, capacitive touch screen* Feature-rich (Laplace transforms, FFT, etc)* Excellent button layout -- especially for HP* Textbook (awesomely implemented), Algebraic, and RPN entry modes available.Cons:* Durability. All HP calculators are cheaper quality than their TI counterparts, but the Prime feels like a $20 Casio* Li-Ion battery will die in short time even with no use. No good for storing in a drawer until needed. Same applies to Nspire CX* Buggy. HP really needs to focus on testing and QA more before releasing their products. Hopefully, future firmware updates will improve this aspect.I have barely skimmed the surface of this calculator so far, but if anyone has any questions about it, feel free to ask them here

author: jonmarx
author_rank: Contributor
timestamp: January 15, 2014, 09:52:03 pm
content: That's an impressive collection of calculators!I have a HP-28S, HP-48G and HP-50G, but the 50G is just gathering dust mainly because I couldn't get used to its keyboard layout (I like the big ENTER key of the older models). So the 48G - either the real thing or the Android emulation on my phone - is my choice for day-to-day use.If I bought a Prime I'd be worried it would end up in the drawer with the 50G.So how are you finding the Prime? Is it your favourite or do you find yourself going back to the older models?

author: olsenn
author_rank: Frequent Contributor
timestamp: January 16, 2014, 04:46:03 pm
content: QuoteI have to say that apart from the poor build quality, the Prime is my new favourite calculator! If I had to only choose one calculator to keep, it would probably be my TI-86, just because I feel that it is more trustworthy as a long-term investment. However, currently having both, I don't ever use the TI-86 anymore.The HP prime does everything that the other calculators do and more; with the xception of 3D graphing, which (until a future firmware revision) requires a third-party app to do. It has the large 'ENTER' key (like the 48) and does include RPN... However, textbook entry mode is FAR superior! I am even impressed so far with the battery life, which I would have sworn would not have been anywhere near as robust as it is.