Damn...they're not fucking around here. That's awesomely excessive. I've never really been one to drool over fancy calculators. But this one looks pretty fucking awesome.
I have a CASIO CFX-9850 GB PLUS with 64 KB memory, and it's been the most useful gadget for spreadsheet-style graphics and data analysis. Since it has a 3 color display, it's very easy to visualize lots of different datasets.
As far as I know, they don't make them anymore, which is a shame. They were great. Slow BASIC, but the BASIC was amazing and easy to use.
I just tried the ln(x²) integration example on my ancient TI-68 (built in Feb 1991) - unfortunately the accuracy depends on judicious choice of numerical integration intervals (it uses Simpson's rule). It seemed to give best results with about 25 intervals, taking about 7 seconds to come up with 717.7575466854 (more intervals result in overshooting the correct answer).
I stick to my HP-50G (which is pretty much the best all-around calculator ever made) and intend to eventually maintain the iOS emulator myself, as it seems there is so little interest.
I do not understand why people do not use calculators, if you are in any engineering profession, it makes life so much easier. No, wolfram alpha, google, siri, python or bc are not the same thing at all.
>No, wolfram alpha, google, siri, python or bc are not the same thing at all.
Why not? A combination of the plain old Windows calculator (scientific and programmer modes) and DDG/Google for unit conversions has worked well for me for years, and doesn't require that I move my fingers off the keyboard.
Because you can't use these tools on many occasions, they don't always do exactly what you want, and accessing them is slower than using a calculator. The devil is in the details. Such as being able to quickly switch to engineering notation to display values applicable in electronics.
Also, I often want to do a series of calculations, for which an RPN calculator with a stack (you can see the top 7 levels) is uniquely suited.
As another example, unit conversions (basically, convert between every unit known to man) is something I use every day. It takes about 6 keystrokes to convert from anything to pretty much anything on a HP-50G.
> The EU General Data Protection Regulation (GDPR) requires me to put this shit here. I don't use cookies (at least, not knowingly!), except for myself, when I must log in to write posts and deal with the comments. If WordPress or one of its plugins uses cookies for whatever reason, I don't give a dead rat's ass on them, and I don't feel responsible.
And now, for the bureaucrats in Brussels and Strasbourg, the following nonsense:
This site is (probably) using cookies for some reason unknown to me (most likely to give you the best experience etc).
You can find out more about which cookies are used or switch them off in settings.
I'm sorry, but you don't get to deny responsibility of what goes on your website, and I find it frankly concerning that you are unaware of what is using cookies (it's StatCounter, just FYI).
On topic, I don't think the author of this article understands how the calculator he's using work; the calculators (at least the Casio one; I have the 115 ES Plus and I think it's functionally identical to the 991 ES Plus) are actually just computing the integrals numerically and then converting to fractions because the error in result was smaller than the the threshold needed to convert it to a fraction. There is no "smarts" (i.e. a CAS) involved.
> just computing the integrals numerically and then converting to fractions
> because the error in result was smaller than the the threshold needed to convert it to a fraction.
Then why can't they display 9 instead of 9.000000007? What is that threshold if 0.7e-9 not small enough? And, are you telling me that computing integral(sin(x)dx from 0 to pi/3) can be done with better precision than 0.7e-9, whereas arcsin(arccos(arctan(tan(cos(sin(9)))))) cannot?
Otherwise, of course I don't know how these devices work internally. But have you designed one, or you're just assuming things?
I'm basing this on experience using one; I have no "inside information" on how they work so I'm doing my best with my insight. Here's what I've found just by messing around; if you want details I can post the "experiments" I did to get these:
* The largest epsilon that the calculator is willing is confident about showing to the user is about 10^-13. (0.1 + 10^-13 - 0.1 = 10^-13, 0.1 + 10^-14 - 0.1 = 0)
* The calculator will show about 10 digits of precision. (0.1 + 10^-10 = .1000000001, 0.1 + 10^-11 = 0.1)
* Rounding seems to occur at the last digit of internal precision, perhaps at a 10^-14/10^-15 digit that isn't shown? This might mean the calculator is using double precision. (.5-10^13=0.5, .5-10^-14=1/2)
I think the results you got are pretty consistent with this. First of all, the sequence of trigonometric operations you performed are quite lossy, since you're exercising a very small range and you perform them repeatedly, which magnifies the error. Performing the integral is quite accurate; even a simple midpoint Riemann sum with 1000 subdivisions is accurate to one part in 10^12).
FYI, you seem to have been shadowbanned (I have chosen to vouch for the one you made here because it was somewhat reasonable and so I could respond to it), which is not surprising considering your other comments.
As for shadowbanning... all I want to say is this. IMNSO opinion, whoever chooses to comment on places like this or like Reddit is an highly impolite, because that's what blogs are for, and commenting is allowed on my blog (moderated, so one wouldn't see a comment right away).
I am sick of people ranting here or on reddit like: "oh, look of what crap some guy is saying somewhere," or "he's wrong wrt to this thing" ... but why on Earth aren't such comments made AT THE ORIGINAL BLOG POST?
If and only if the OP deletes your comment, only then posting here makes sense: "that narcissistic guy didn't accept comments, so I'll put them here: blah-blah."
It's very sad that enthusiasts running a wordpress blog to share their interests with the world now have to hire lawyers and tech experts to evaluate their sites and determine to what extent all their plugins are legally compliant or face comments assaulting them, and their comments responding stricken.
The result is that interesting and useful information being shared by amateurs is systematically being targeted and banned from the internet. Soon everything will be corporate views only thanks to these laws and their intolerant fundamentalist advocates, both which are intentionally destroying vast parts of human culture and knowledge. For this reason, these laws, and their advocates both, are extremely evil entities.
> For this reason, these laws, and their advocates both, are extremely evil entities.
That's some nice alliteration you've got there, but I'm still of the opinion that you are responsible for what goes on your website. I run a blog just like the author does, but I unlike him I am not flippant about legislation designed to protect my readers' privacy. Since it's my website, I can ensure that I don't run cookies at all, which means I don't have to hire "lawyers and tech experts". And finally, I'm pretty sure the comment was automatically flagged due to its tone and the fact that the account was new.
If something is not able to selfregulate then external regulation must be accepted. And such external regulation tends to be less nice to its subjects than selfregulation, almost by necessity. If the web would not have gone overboard with tracking and data abuse, then EU wouldn't have needed to put up all these stupid laws. Alas, the greed of mankind made it no so, so here we are
> Simply put, CASIO is the king, and fx-991EX, whatever you call it, is the mother of all calculators, both in build quality and features
Let me introduce to you the DM-42, the ultimate calculator
https://www.swissmicros.com/dm42.php
Precision? 34 decimal digits
Build quality? Steel case for starters
Keypad? Harks back to those classic HPs in feel
Screen? High-res, high contrast
Performance? 24 MHz ARM core
And best of all? Fully free firmware that you can verify and modify to your hearts content.