Keisan Casio is shutting down | Hacker News Reader

Keisan Casio is shutting down

keisan.casio.com

151 pointsthazework46 comments

I had never heard of this site. Now I am sad. It seems useful.

I recently discovered omnicalculator.com, which seems similar.

Can it do up to 130 digits precision?

I wish they would open-source the back-end code, so we could self-host.

Is there even any backend? Sounds like a collection of basic numeric algorithms, it should be possible to replicate almost all of them with little to no effort on either JS/WASM or Python/Pyodide.

To me this looks like an early and Japanese variant of what Wolfram Alpha is. Am I wrong?

It was a bunch of static calculators while WA uses NLP and is more-or-less superior in almost every use case. While there isn't a comprehensive list of specific conversions possible on WA, there are many examples categorized on the home page.

https://web.archive.org/web/20230831005411/https://keisan.ca...

Disclaimer: I'm partial to Xcas and HP Erable.

It looks like only the English version is shutting down. The Japanese version seems to be going strong: https://keisan.casio.jp/

Looks like the Japanese forum is going offline too:

https://keisan.casio.jp/keisan/user_forum/

Can someone explain what this is/was?

From Merlot.org: Keisan Online Calculator site is provided and supported by Casio Computer Co., Ltd. This site contains various Free Online Calculators that enable you to carry out high accuracy calculation using arithmetic operation system with variable number of digits uniquely developed by Casio.

A huge collection of fill in blank formulae, like "Travel distance at 10 kph for 10 hr equals to 100 km or 62.137 mi", but seemingly everything the users or their employee needed more than once.

For me the high precision calculator (with up to 130 digits precision) was the most (only?) useful part of the website. It was a life saver if you needed it. Really sad to see it go.

https://keisan.casio.com/calculator

Do you have an example of when 130 digits of calculator precision are needed?

For root finding algorithms in some edge cases it helped me decide the multiplicity of a root. Also, when calculating constants I wanted to make sure that the result was as precise as possible without any rounding errors introduced in the calculation.

Solving a "Ponder This" challenge like [1] (and getting the full bonus).

[1] https://research.ibm.com/haifa/ponderthis/challenges/August2...

Couldn't you simply use arbitrary precision floating arithmetic with i.e. Python?

Yes, python with import decimal can be used, as well as Linux bc, but the question was what you need so much precision for.

I've been nerd sniped.

What are the "rules" of these problems? Are you allowed to use calculators and programming? Or should the solutions be pencil and paper only Olympiad-style?

> I've been nerd sniped.

Huh, looks like I'm one of today's lucky 10,000

https://xkcd.com/356/

Yes, you can use all resources available to you. Most challenges involve some amount of programming.

If you want a self-hosted replacement for Keisan I strongly suggest looking at Qalculate! https://qalculate.github.io/

Qalculate even looks up relevant facts online such as when used for real time currency conversion rates, e.g. 1000 JPY/USD

(Self promotion) if people like the Casio style calculators, my app is heavily influenced by Casio’s scientific calculators. The editor works almost exactly like theirs, but it has a modern keyboard that’s optimised for touch screens. The rendering uses the LaTeX font too

As well, you get a few dedicated modes, like unit conversion, date calculations etc.

https://jacobdoescode.com/technicalc

Why don't you put the legacy, unmaintained Android version on F-droid?

I’ll look into it

The high precision calculator was a true gem. I have used it a few times when I needed more precision than the 64bit that Javascript gives me. Is there an alternative somewhere?

Fabrice Bellard's numcalc.com is okay if you just want JavaScript with more precision.

It doesn't have the same satisfaction of just writing down the numbers and operations on them, but "python3 -c 'import decimal; decimal.getcontext().prec=130; print(decimal.Decimal(2).sqrt())'" will give you any desired precision (130 here) and I imagine roughly the same gamut of mathematics operations as Javascript.

I simply use calc in emacs, it has arbitrary precision (really bound by process memory limit on modern systems).

Linux (and MacOS homebrew) offers the arbitrary precision calculator bc:

    > bc -l
    sqrt(2)
    1.41421356237309504880
    scale=64
    sqrt(2)
    1.4142135623730950488016887242096980785696718753769480731766797379

https://jrsinclair.com/articles/2020/sick-of-the-jokes-write...

Seems like someone would have made a self-hosted clone of this on github by now.

I loved the high precision calculator and used it occasionally. Sad to see it going.

This is something I would love to see open sourced but I know that’s not going to happen.

Site looks pretty nice. Too bad I just heard of it. I guess no easy way to archive this. This is my biggest grip with all that followed straight HTML.

No, only the english part of the website is closing.

No, as another poster pointed out:

https://keisan.casio.jp/keisan/user_forum/

掲示板は2023年9月20日をもちまして廃止することになりました。これまでご利用ありがとうございました。

I would say that it's unclear; that announcement appears to apply only to the Keisan Casio user forum.

A machine translation follows:

> The bulletin board will be abolished on September 20, 2023. > Thank you for using our service. > The bulletin board is a space where members can exchange information and opinions. Please respect each other's opinions and personalities, and post and reply with good sense.

Keisan means calculate. I've been to the site on occasion but I'm pretty sure I won't be missing much.

this is a sad event

it will live on in archive.org/.is…

No, the calculator is implemented server side, archive.org cannot backup that.

Seems like a great use case for wasm. Then it can be cached.

JS would suffice.

JS has bigint, but it doesn't support trig operations. Is there something in npm that supports it?

There are game engine in JS, x86 emulator have been written in JS, JS isn't limiting functionality.

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