Qalculate – A multi-purpose cross-platform desktop calculator

https://qalculate.github.io/

by pantalaimon • 3 years ago

220 130 3 years ago

qalculate.github.io

curiousfab• 3 years ago

Fantastic tool. It also has a command line version which has almost completely replaced `bc` for me.

jstanley• 3 years ago

The most annoying part about bc is always having to type "scale=5" before you start otherwise it makes you think all your answers are integer.

danadam• 3 years ago

"bc -l" runs it with scale set to 20. Also preloads some math functions.

fuzztester3• 3 years ago

What danadam said.

Also:

https://www.gnu.org/software/bc/manual/html_mono/bc.html#TOC...

Environment variables

BC_ENV_ARGS

drbig• 3 years ago

It is a very versatile piece of software indeed. The minimal mode window is a great pop-up calculator that can do a lot, including conversions and working with physical units.

Highly recommend!

integricho2• 3 years ago

Not to criticise the application, but how realistic is that such an application weighs ~70MB?

procone• 3 years ago

Are you really so strapped for disk space that 70MiB impacts your user experience?

EDIT: The parent comment is disingenuous: the application isn't even 70MB. It's only 70MB if you download the windows edition with vendored libicu (unicode, 31MB) library. It weighs around ~20MB on linux distributions, which is insignificant.

not_a_shill2• 3 years ago

Even worse this kind of critique is actively cancerous to new developers if they actually think that people outside of HN care about this.

Development productivity over everything. Features matter not app binary size.

baal80spam• 3 years ago

I knew it would be fairly big but 70MB is ridiculous. I weep for today's software.

pantalaimon• 3 years ago

qalculate-gtk is 3.7M on my system with libqalculate.so.22.17.4 weighing in at 5.7M

dist-epoch• 3 years ago

Imagine if it was implemented in Electron, not in Qt. It would have been 300MB+ then.

FreeFull2• 3 years ago

Looking at qalculate in Arch repos, libqalculate comes in at 14.94 MiB, and qalculate-qt at 3.37MiB, so 18.3 MiB total. If you're looking at the Appimage, the rest of the size would be from the libraries it depends on, like Qt/GTK+

wffurr2• 3 years ago

So a smallish C++ static binary then.

Aardwolf3• 3 years ago

libqalculate is the mathematics part and the command line tool, while qt is GUI, so it's surprising the GUI part isn't the larger one of the two

eviks11• 3 years ago

oh, it's way more than that, on a Mac via brew it needs 600M QT and 50M gtk+3 and a couple of dozen M for other dependencies

mappu• 3 years ago

I think the real issue here is the brew formula - the Qt runtime should be under 50MB (over if you include the chromium packages). Only the full development toolchain might be close to 600M and that clearly isn't needed here,

rom1v• 3 years ago

There is also the command line version: `qalc`.

I use it since I discovered it.

Aachen2• 3 years ago

Same. I was happy with `apt install calc` (I think nowadays called apcalc) for years because it does arbitrary precision and isn't as awkward as a python shell or so, but qalc is clearly a step up with support for units and solving

    $ calc 2^x=4
    x is undefined
    $ qalc 2^x=4
    ((2^x) = 4) = (x = 2)

I used the above for determining after how many years a given inflation rate doubles a price (1.03^x=2)

I think my most recent real-world application for units calculation was about how much energy a device uses in kWh after a year, given that it draws 10W during office hours:

    $ qalc 10W*(8h/day)*1year to kWh                                                                               
    (10 * watt) * ((8 * hour) / day) * (1 * year) = 29.22 kW*h

It even does time calculations: 13:37-08:00 tells you that you've been working for about 5.6 hours.

I don't know why this isn't the universally used command-line calculator. I have it on my phone as well via a Debian subsystem and it's the best

kbd2• 3 years ago

$ qalc 10W(8h/day)1year to kWh

Question: why didn't you need quotes around the first expression? Both Zsh and Bash error on that command without quotes. Are you using nushell?

glibg10b• 3 years ago

I use it as my calculator app on my phone

rnallandigal• 3 years ago

I have it bound to `$mod+c` and launched as a floating window in i3. It integrates very well into my workflow as I can just quickly launch, perform a one-off calc, and close it whether I'm in a terminal or elsewhere. Since it saves history, I can always relaunch it and continue where I left off as well.

nh23423fefe• 3 years ago

i like the rpn mode

kqr• 3 years ago

Huh, yeah, it does do RPN. This is actually looking like a serious replacement for my current daily driver, Emacs calc.

cyfex2• 3 years ago

I have `$mod+c` bound to rofi-calc [1] which I find even more convenient.

1. https://github.com/svenstaro/rofi-calc

Svenstaro• 3 years ago

Glad you like it. :)

xchkr1337• 3 years ago

I hve a global shortcut to open a Julia REPL session and I use that to perform any sort of quick calculations instead of a GUI calculator. The best thing about this approach is that I can always create new functions for stuff I use often.

bobmaxup• 3 years ago

I am not sure if it is of interest to you, but from the cli, qalc's REPL is much faster to start when compared to julia

sundarurfriend• 3 years ago

The best thing about this approach is that I can always create new functions for stuff I use often.

Do you put those in your startup.jl? Do you have a Startup package like some recommend for Julia 1.9+?

thumbuddy• 3 years ago

Qalc seems like a better calculator to me and is more stable somehow despite being written in I think C++. Not having to download a huge programming language taking up GB of space, research an ecosystem and import ten packages sounds ideal. I prefer python or R and sometimes even BC to Julia for terminal calculating anyways...

I'd let the post about qalculate be about qalculate here.

Aardwolf3• 3 years ago

I tried this in cinnamon. But I use multiple desktops and if qalculate is already on another desktop, the experience is pretty bad since it doesn't move to this one (and I do want its 'allow only single process at once' enabled so settings save properly)

Does there exist a solution for that?

VadimPR• 3 years ago

Are there prebuilt binaries available for macOS? I'm running the GTK version on an m1 and it always takes a few seconds to get going.

29athrowaway• 3 years ago

At this point just use a CAS or a TI calculator emulator.

zzbn00• 3 years ago

I also tend to just use a CAS, specifically maxima (either commandline, via emacs, via wxMaxima or via notebook, see https://github.com/robert-dodier/maxima-jupyter ). It has the plotting, great units etc, and also incredibly handy to do things like a taylor expansion around a point with no effort.

If not maxima, then the old M-x calc will usually do the job

anagri• 3 years ago

do you have a Mac installer available?

also you need a designer. the website looks like from the 2000s.

thanks for sharing the app.

wffurr2• 3 years ago

A quick click shows that it’s available on home brew and Mac ports.

I like the 2000s website style. It’s functional, simple, and loads very fast.

eviks11• 3 years ago

what the quick click doesn't show is that brew will require ~700mb of dependencies and still installs as a cli app, not an GUI app bundle

pluijzer• 3 years ago

Yes this website needs a huge full screen video of models in business attire making calculations on a white board. When scrolling down I don't wish to find out what it does but would like some quotes from people saying how it changed their lives. Some transitions would be nice, the ones that make my fans spin, it gets cold here in the winter. Without it this website is barely usable.

fuzztester3• 3 years ago

Totally.

Along the same lines, I'm nearly Goad Complete (TM) with an amazing SaaS called Append-Slash-Ess as a browser extension. It does what you would expect, at the click of a mouse or touch of a finger, no need of keyboards, which are so last century. We aim to obsolete them so we can rake in, oops, take on our mission of improving the world.

And since our team is made up of (literally) outstanding ex-Ghroaglers, we'll only support the Ghroan browser, of course. And it'll detect and reject others, for the benefit of everyone.

doodpants• 3 years ago

So, you think the website would be better if it:

- had low contrast text in a thin font

- had pointless animations of content fading in as you scroll down

- had a GDPR cookie consent popup

- popped up an interstitial form asking for your email address so you could receive their newsletter, but only after you've had the site open for 30 seconds and were in the middle of trying to read it

- was completely blank if you disabled JavaScript to try to avoid all of that nonsense

No thank you; the current design is unironically perfect IMHO.

gapan• 3 years ago

Can you please point me to a website from the 2000s that looks like this? A wayback machine link would do. Because I definitely don't remember websites from the 2000s looking like that.

The website's design is fine.

akho4• 3 years ago

what kind of satire is this

cyfex2• 3 years ago

It's a really great calculator for all sorts of stuff.

I use many of the following almost daily:

- currency conversion: `x USD to EUR` or `BTC to USD`

- time calculations: `now - 27 hours`

- unix epoch conversion: `timestamp(now - 3 days)`, also `stamptodate()`

- unit conversion: `34 oC to oF`

and more.

Works really nicely with https://github.com/svenstaro/rofi-calc

blondin• 3 years ago

i wonder why calculator apps are so popular

grotorea• 3 years ago

It's the oldest use-case for non-human computing and one the things computers are best at compared to humans.

akho4• 3 years ago

They compute things on a computer

“Popular” is a bit of a stretch though, I’m not aware of any fanclubs

LispSporks22• 3 years ago

I use calc mode in Emacs for that kind of thing. Any idea how the two compare?

netbioserror• 3 years ago

If you want a lighter-weight package featuring a plaintext REPL, a large library of functions, function definition, arbitrary precision, and more (minus solver capability), give Speedcrunch a try:

https://heldercorreia.bitbucket.io/speedcrunch/

lholden• 3 years ago

I switched from Speedcrunch to Qalculate a while ago. I don't actually remember exactly why I switched at this point. (I think due to a lack of updates). Qalculate very similar in many ways, but I do like the interface on Speedcrunch better (after hiding the keyboard). The new UI for Qalculate has a similar enough feel to Speedcrunch that I've been happy with it.

patrec• 3 years ago

Qalculate has a plain text repl (qalc), as well. And, as far as I know, all the other things you mention. Speedcrunch might be awesome for all I know (never tried it), but your comment does not really shed any light on why one would pick it over qalculate (what does "lighter-weight" mean? It's not like qalculate takes minutes to start up or is hard to use).

ciupicri2• 3 years ago

The plain text qalc doesn't compare with Speedcrunch. How do you copy & paste for example? Speedcrunch also has a shortcut for putting the result into the clipboard.

You can make Speedcrunch look like a good old fashioned bc session, whereas Qalculate puts way too much stuff on the screen. It misses a simple REPL mode.

badtension• 3 years ago

Speedcrunch is great but has (had?) a very annoying bug: was pretty slow after a while. You need to manually clear the history to make it load fast again.

I have it on speed dial (pause / break key to open and close) and use it all the time.

ziml772• 3 years ago

A note to anyone using a high DPI display: you can build this from source and get a version that scales itself cleanly instead of forcing the OS to make a blurry mess out of it.

eviks11• 3 years ago

what changes would you need to make so that the build isn't blurry?

pxc• 3 years ago

In college, I started out with SpeedCrunch because it comes with many KDE-based Linux distros as their default calculator. I eventually went on to play with a few alternatives and ultimately settled on Cantor, which is a nice, notebook-style frontend for pretty much every mathematical programming environment you can think of (including Qalculate!). At the time, I really liked using it with Maxima (and sometimes R).

https://cantor.kde.org/

themodelplumber2• 3 years ago

Plus you can quickly build websites with speedcrunch IIRC

Edit: https://www.friendlyskies.net/speedcrunch/

Kinda funny but also impressive in its way...

poetaster6• 3 years ago

I'll +1 speedcrunch It's also been built for off-broadway mobile OS Sailfish.

fuzztester3• 3 years ago

RealCalc free version from Quartic on Android is not bad. Not comparing it to Qalculate.

And it has a really cool physical-world electronic calculator look, hence the name.

freedomben2• 3 years ago

I use RealCalc on Android as well! Been handy to have for years. I bought the paid version and have been pleased with the purchase.

michaelcampbell• 3 years ago

Definitely a purchase I have never regretted.

georgeburdell2• 3 years ago

As an engineer, I usually can just pop my expression into Siri/Spotlight or Cortana with a hotkey and get the result just fine. What kinds of calculations are people needing more for?

discordance• 3 years ago

Can you do dimensional analysis in Siri?

georgeburdell2• 3 years ago

I’m not sure what dimensional analysis means in this context. Is this like “does N-m = kg x m2/s2”?

marcosdumay• 3 years ago

Or solve equations?

I imagine Siri has a database of constants, but is it usable?

themodelplumber2• 3 years ago

Can it do ans* etc. Is there a history of expressions and results. Is the history on-screen while next expression is typed. Is there a current result indicator, i.e. live update of the expression result as you fiddle with parameters.

Just what's coming to mind for basic daily use here.

jnsaff2• 3 years ago

I find it quickest to CTRL+SHIFT+K if I'm in the browser or run `iex` or `python3` in terminal to calculate something ad-hoc.

eviks11• 3 years ago

The "ultimate" calculator wouldn't use the same irrelevant-in-PC physical number buttons paradigm, taking up more than half of useful UI space

icegreentea2• 3 years ago

shrug when I ran it the first time, the default GUI is a menu bar, entry area and history. Like: https://qalculate.github.io/images/qalculate-qt.png

eviks11• 3 years ago

and I got the screenshot advertized on the main page

orbital-decay2• 3 years ago

irrelevant-in-PC physical number buttons paradigm, taking up more than half of useful UI space

Calling it irrelevant is a bit like calling vim irrelevant. Classic calculators don't use REPL, they are designed to minimize the number of keypresses required to input your problem and explore it in the intuitive manner. They use highly efficient modal input languages (kind of like vim). Besides being efficient, these languages tend to have one-off commands you have to remember. Having a cheatsheet on your screen by default is useful for discoverability. In the algebraic calculator paradigm and their typical use cases (napkin math), having a history is not very useful (unlike in RPN where having the stack on the screen is nice).

That said, Qalculate is weird in that it uses a REPL and the input line, which is much slower and clunkier than the algebraic input, but still tries to mimic a classic calculator. It's also slow to start. Not sure what's its use case, as it offers neither speed of a classic calculator nor the feature set of full-fledged math software.

eviks11• 3 years ago

This doesn't make any sense, what kind of cheatsheet do you need to discover numbers on your keyboard???

What kind of efficient modal input language is it where you have to move your hands off the keyboard and move your mouse to press a button to insert a number?

wander_homer2• 3 years ago

It's also slow to start.

It's launching instantly here, with cold caches.

zamadatix• 3 years ago

If every PC had a number pad I'd agree but efficiently using the top row number keys for both symbols and numbers is a tall expectation for most users to default to. Doubly so when you factor in holding shift and memorizing the operator locations in that row. A full point and click is a great default IMO, even on PC. I'd also argue in the case of devices with a numberpad you're unlikely to care as much about the wasted UI space anyways.

dTal2• 3 years ago

Feel free to turn it off. The "ultimate" calculator wouldn't deny the option to have the classic button paradigm...

eviks11• 3 years ago

That's not a good excuse - that would be an option, not the main UI, and if it weren't the default, than the dev could've realized that that space could be used in a much better way

bityard• 3 years ago

Anyone else just use the Python REPL as their desktop calculator?

idanp2• 3 years ago

yes, with modifications - https://github.com/idanpa/calcpy

poetaster6• 3 years ago

Looks really nice! I wanted to ask if 'matplotlib' was strictly needed since it's a big depends?

oneshtein• 3 years ago

bc -l

freedomben2• 3 years ago

Yes! (although ruby (irb) instead of python). It's amazingly useful to be able plug in expressions in a single line of text format. Though for more complex expressions, something like qalculate looks nice to me.

nuxi• 3 years ago

For one-off simple calculations I just use awk, with this handy function in my .bashrc:

  function calc() { awk "BEGIN{print $*}"; }
  
  # usage in bash
  $ calc 'sqrt(25) + 2**3 - 17.17'
  -4.17

ceving• 3 years ago

Have Droid48 on my phone. I am infested and will never use a calculator without a stack.

stonogo• 3 years ago

This program also supports rpn mode with a stack.

amelius2• 3 years ago

If this evolves a little further, you get Jupyter notebooks.

akho4• 3 years ago

Doing units in Python is a pain. No easy RPN/stack mode. No flexibility in parsing. Vector, matrix, and date maths require weird syntax. No good concept of infinite number.

Stuff it. I’m just reformulating https://qalculate.github.io/features.html ; you can do that yourself.

amelius2• 3 years ago

https://docs.sympy.org/latest/modules/physics/units/index.ht...

FpUser• 3 years ago

Beautiful piece of work. Kudos

poetaster6• 3 years ago

I wanted to chime in as a calculator dev dude. Qalculate is really nice if you want the kitchen sink, which I do on the desktop. I also, depending on the task use speedcruch which others have mentioned.

Using https://github.com/ArashPartow/exprtk I have one calculator with a repl at 512kb, including a QML wrapper. I have a combined rpn calculator using sympy (based on the work of others) with exprtk as a 'programmer's calculator' on the side (https://github.com/poetaster/fibonacci). And several QML apps for symbolic CAS using sympy.

I have way too many calculators. They are so much fun to build. Now I ask myself, port the Qalculate methods to macros for exprtk or check out using libqalculate? I'm not sure. exprtk is so light? And adding macros discrete.

poetaster6• 3 years ago

I forgot to mention in my last comment that https://github.com/vetux/qcalculator is also a nice qt based, exprtk using calculator with a python interface and higher floating point precision than plain exprtk.

6510• 3 years ago

I'm told if you don't use floats the computer will explode and the whole city will burn down. End times, armageddon scenario pretty much.

ghkbrew• 3 years ago

Thanks, I'll stick with Rstudio.

despi• 3 years ago

Qalculate is great. I also use insect on the terminal for quick calculations or conversions

https://insect.sh/

squarefoot• 3 years ago

Obligatory mention for bc, a command line arbitrary precision calculator and language.

https://en.wikipedia.org/wiki/Bc_(programming_language)

qwerty456127• 3 years ago

Lisp is the ultimate desktop calculator. But this one looks nice anyway.

sombragris• 3 years ago

I love qalculate. Now Slackware (my distro) ships libqalculate, and then it's trivial to build a frontend.

I loved Qalculate back when it was a KDE3 application. In KDE4 times the UI switched to GTK+, but recently the dev added a newer Qt frontend which is really nice save for the fact that it doesn't have an app menu other than a hamburger menu not really accessible via keyboard; you must use the mouse for it.

I'd love to see a KDE Plasma frontend again with the more traditional layout. The app is great and powerful.

Qalculate – A multi-purpose cross-platform desktop calculator

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