
Tydlig – Calculator Reimagined for iPad and iPhone - Istof
http://tydligapp.com
======
smikhanov
Great to see more people attacking the underserved math app segment on the
iOS.

I'm the author of Scalar ([http://scalarapp.com](http://scalarapp.com)),
another calculator replacement for iPhone / iPad. Just tested both versions of
Tydlig very heavily, looks like the author ran into lots of the similar
math/UI problems as I did when I was working on my app. :) Some approaches he
has chosen look similar, some are unique.

Great work, good luck!

~~~
jckt
This looks rather good (sadly no iDevice). Looks as if Apple came up with it,
if they weren't so silly with the way they applied their skeumorphism.

I always imagined that if you were aiming for the mathematician market (huge
market!!1 /s) you could have an app like that except on a tablet you'd use
with a pen. Then you'd just write down calculations and OCR would figure out
what you are trying to calculate and do the number crunching (where
applicable), and intelligently recognise variables and a lot of different
mathematical functions (I just don't like the whole process of going back and
forth between my TI and my legal pad). That'd be a mathematician's (or just
mine) wet dream.

~~~
mnx
Something like that exists(for android): MyScript Calculator. It's probably
not powerful enough for a matematician, but works for me.

------
csmuk
No RPN. Neckbeard status confirmed.

Calculators are still an unsolved problem for me on glass devices to the point
I still religiously carry around an HP50G even though its 6x the size of my
phone. Also from some bad experiences, it appears that some "app" calculators
are also seriously badly implemented. Even basic trig ops can return stupid
values at extremes which makes them untrustworthy. Plus none are reasonably
programmable.

My use cases are base conversions, simple CAS stuff, basic engineering
calculations, unit conversions, financial (TVM etc) and generic math. I also
canned a lot of knowledge in RPL programs over the years from fuel
calculations to diagnostic tools and dice rollers etc.

Please can someone solve all these problems (without doing half arsed HP calc
emulation).

~~~
Lazare
Yes. I really want a decent, pretty, RPN calc on all the platforms I use.
Which rules out any HP emulator. I've _got_ several amazing HP calcs gather
dust in a drawer; I want something better than that.

I've been pleasantly surprised with the built in calculator that ships with
OSX; it's got a decent RPN mode, good keyboard support, and a nice stack
display. Not brilliant, but better than what I've found for Windows or
Android. :-/

~~~
gcv
I use m48+. It's a decent replacement for my trusty old HP48.

~~~
acqq
Yes m48+ is the best way to have HP 48x. I'd also like to have the emulation
of my HP 28S, I'm more used to it.

------
jckt
Graphing functionality on a phone reminds me of an old TI calculator. I really
don't know why recent OSes (be it on PC, smartphone, tablet) always came with
such feeble calculators. It's not like TI calculators are difficult to use.
Sure if all you want is add/min/mul/div functionality the TI is essentially a
traditional calculator, and then behind that you've got all these nifty
graphing utilities. It's not like a graphing calculator app is going to be
_that_ difficult to program, or going to be large in size. But no, in 2013,
vanilla OS installations are stuck with a calculator app that has less
features than that of a computer a few million times less powerful.

(Now I feel bad; bitching and complaining is against the Open Source Spirit).

Edit: I do recall that OSX comes with something similar, except that not many
people actually know of it (as far as I can tell, from my friends with OSX).

~~~
tolmasky
Just a musing: perhaps its considered not as valuable an investment to program
since a (the?) primary market is students, and students are probably not
allowed to use phones on tests for obvious reasons (internet connectivity,
texting questions to each other, overall distraction). However, TI's are state
approved or whatever.

~~~
visakanv
It's so sad that kids with iphones aren't allowed to use phones on tests.
They're being tested in an archaic context for archaic purposes. Under what
circumstances are people going to be working without internet access? School
has a lot of catching up to do with the real world. :(

~~~
withad
For any field, there's always some basic knowledge that anyone studying or
practicing it simply has to have if they're going to be at all effective. A
well-written test should be checking that the students have acquired that
knowledge (which can be much of the course content) and can apply it
appropriately to problems.

Anyone with an internet connection can easily find out, for example, how to
add together two ints in Java. But if someone took an introductory Java course
and couldn't do that at the end of it, then they don't deserve to pass because
they've clearly not learned what they were supposed to. If they were actually
trying to program something and had to look up basics like that every time
they used them, they would be so slow as to be completely useless. Or consider
someone with a more time-critical job like a surgeon - they can do specific
research beforehand but some level of knowledge (surgical techniques, how to
use their tools, anatomy, etc.) is simply going to have to be in their head at
the moment they need it or their patient could die.

Also, phones and internet access don't just provide knowledge, they're a way
to communicate with everyone else in the room. If you want to see if any
particular person has actually learned the material, you obviously can't allow
that.

~~~
lowboy
> If they were actually trying to program something and had to look up basics
> like that every time they used them, they would be so slow as to be
> completely useless

Isn't that the point of timed tests? You can structure a test such that the
person who needs to look up how to add two ints in Java will waste so much
time that they wouldn't be able to finish the test. And if they can search for
and apply this knowledge quickly enough, then maybe they've proven that they
won't be slow if they have to do it in the real world.

My favourite exams were open book but still hard/long enough that if you
didn't already know 95% of the material, you simply wouldn't have time to
complete it.

~~~
jbri
On the other hand, if you allow outside communication (such as unrestricted
access to the internet), you open the door for "I'll pay someone who already
knows this stuff to phone in the answers for me" \- which isn't generally an
applicable skill in the real world.

As an aside, I hated open book exams - if you were talented and knew the
material, you could typically blast through a closed-book examination in half
the allotted time and get out of there, while the open-book exams were far
longer and more tedious.

~~~
tbirdz
>"I'll pay someone who already knows this stuff to phone in the answers for
me" \- which isn't generally an applicable skill in the real world.

I would argue that this is also a valuable skill. Knowing who to hire,
assessing the person's abilities, figuring out if they can actually get the
job done in the time allotted. Sure it's not at the same level that a hiring
manager at a tech company in the real world would have to make, but then again
the normal CS test questions aren't at that level either.

------
stormbrew
This really seems much more like a freeform spreadsheet than a calculator to
me. Which is also a cool idea, obviously, but I find it interesting no one
else has made the same observation.

------
zarify
I basically stopped using "calculators" when Soulver and more recently Calca
came out. Much easier to use and a lot more flexible.

That said the graphing in this looks quite nice.

~~~
Lazare
Wow, Calca is amazing. Thanks for the tip. :)

~~~
peterhajas
Calca is such a great calculator. I've encountered some issues where it
refuses to recompute (systems of equations confuse it when you keep redefining
variables), but I suppose that's not what it's for. I love being able to
define real functions in it. The documentation is also all composed in Calca,
which is helpful.

~~~
ketralnis
I've seen it be really awkward with whitespace, usually when I think it's not
recalculating it's because of a stray or missing space somewhere that's
keeping it from seeing that something is an equation (it tries to auto detect
between equations and markdown).

The common case for me is that I keep a very short-term personal ledger in it,
just the stuff that hasn't hit the bank account yet, like this:

    
    
        chequing = (1,000 # current balance
          - 2  # coffee
          - 15 # groceries
          + 2  # Joe paid me back
          ) => 985
    

But messing up the spacing in any way, for instance like this:

    
    
        chequing = (1,000 # current balance
          - 2  # coffee
          - 15 # groceries
          + 20  # Joe paid me back
        ) => 985
    

(note one fewer space before the closing paren) and now no changes to the
values inside the parens take effect on the total after the => (which for non-
Calca-using spectators should always auto-update based on changes). I copy-
pasted this out of Calca just now and you can see the the total is incorrect.

Sometimes this messes up the syntax highlighting so that it's obvious, but
usually it doesn't, and I'm left wondering why it's not updating.

------
dirtyaura
Great work. A few thoughts from the initial experience:

I like the linked numbers design. As it reminded me of Bret Victor's work, I
was expecting scrubbing to work directly with numbers, which caused
occasionally a bit of havoc, but I think you did a right choice of putting
linking as the main action - touch design is hard.

The free-form infinite layout gives a mindmap vibe: it's potentially great
when you are trying to understand pieces of a problem that you need. The
downside is that the canvas becomes a bit of mess quickly.

The other alternative could be a Mathematica style, free-form document, with
more restricted flow of equations (and text).

Because the organization becomes a bit of problem, undo is a must and solves a
bunch of other problems. I'd implement area selection of equations (initiate
with long tap?) to quickly move things around.

Y-axis could auto adjust by default or quick slider scrubbing should work
directly for axis max-min values.

You probably want a simple document model as this is something between
calculator and full featured computation software. Maybe just save every
canvas when user clears/starts new one

All in all, great work!

------
lajospajtek
Good to see that Bret Victor's ideas outlined in "Inventing on Principle"
start taking some foothold.

~~~
hisham_hm
Impressed to see only one comment, with no discussions, mentioning Bret
Victor. His influence is clear on this work.

------
wsr
As a Matlab enthusiast, this is probably the coolest thing I've seen in years.

Good job guys, I have high hope for this in the future!

------
mwc
The linked numbers are brilliant. Lacking the "in my head" math skills I
should probably have, I regularly whip out Excel to solve the kind of use
cases you can imagine from the linked numbers in the video.

------
airtonix
And now for the majority market share, the android version?

~~~
avolcano
Just because an OS has a "majority market share" doesn't make it a suitable
market. Elegant, minimal premium apps like Clear have done well on the iOS app
store, but it's hard to imagine a $5 calculator app getting much interest on
Android.

~~~
chinpokomon
Why is that hard to imagine? If the application were released for Android, I
would have considered it. I've already purchased several Android calculators.
There's no real basis for your claim, but I say this while I also realize I
haven't provided sufficient evidence to support why Android would be a better
platform. The reason I think a lot of applications like this fail on Android
is that the developers first target iOS and then try to port it to Android
without really _designing_ for Android. The result is something lackluster
that doesn't really work for Android devices.

~~~
corkill
Although you may personally have considered purchasing this calculator on
Android. I think he was hinting at the fact that an IOS user is more likely on
average to purchase an app and pay a premium for it, hence being more
lucrative for developers even with less market share.

"the App Store generated 2.3x more revenues than Google Play."

[http://www.theguardian.com/technology/2013/aug/01/android-
ap...](http://www.theguardian.com/technology/2013/aug/01/android-apple-google-
play-apps)

~~~
troymc
It's probably not a good idea to make a decision for a specific app based on
the average behavior across _all_ apps, unless your app is "average."

A calculator app is an outlier; it is _not_ an average app. It's also an
outlier with real _utility_ \--- so it's something people are more likely to
pay for.

------
diziet
This is great, though there are 15,230 calculator apps on iPhone alone. Tydlig
ranks as #443 in the US for 'calculator', quite a tough fight!

------
ra3
Looks great. Just needs a new name. Tydlig?

~~~
sorenvrist
(Edit: it is swedish and...) Almost danish/norwegian: Tydelig ==
Apparent/Clear

~~~
jsilence
In German the slang word tüddelig means fiddly or flimsy.

------
pfisch
This looks much worse than symcalc.

SymCalc has pretty much all the functionality of a TI-89 including solving
calculus and algebraic equations.

Tydlig looks like it has a nice ui but it doesn't even seem to support
variables....

~~~
jamesjguthrie
Thanks for the recommendation for SymCalc, I've just downloaded it. I had been
using TouchCalc and GraphCalc but this is much better!

------
cormullion
I love this app, and it's interesting to see the innovation in this familiar
space. Oovium for iPad is a great example of fresh thinking. And coming soon,
apparently, is the Wolfram Calculator for iPad, featuring user-programmable
functions:

[http://mvid.wolfram.com/mobile/dannewman_teachconceptsnotkey...](http://mvid.wolfram.com/mobile/dannewman_teachconceptsnotkeystrokes_archive.mp4)

~~~
gcanyon
That interface is a bag of hurt, but it looks powerful.

------
ricardobeat
If you're mainly interested in having all calculation steps visible and
'linked', there is also a great app called Digits
([https://itunes.apple.com/us/app/digits-calculator-for-
ipad/i...](https://itunes.apple.com/us/app/digits-calculator-for-
ipad/id364500115?mt=8)) which is at $0.99 right now.

------
notpg
For the iphone and ipad? You mean for direct interface devices? (is there any
reason this couldn't be applied to non idevices?)

~~~
ketralnis
Because it's written for UIKit for iOS, presumably in Objective C?

------
edoloughlin
_Tydlig supports external Bluetooth keyboards or numpads for really quick
entry_

It's been a while since i did any ios development and this was never a
requirement for me. Can someone explain why an external keyboard is something
that had to be explicitly supported at an individual app level? Surely this
should be an OS-level thing?

~~~
interpol_p
It's not an explicit requirement, but you definitely need to test your app
with an external keyboard to polish the experience.

Here's a couple of situations that can get you when supporting an external
Bluetooth keyboard:

\- Input accessory view. If you use an input accessory view (bar that sits
atop the regular software keyboard), then connecting an external keyboard will
cause the software keyboard to hide but keep the accessory view on screen.
This is great — but if you had any controls underneath the keyboard
(especially on iPad) that required the user to dismiss the keyboard to get to
them, then you have to build a way for them to 'dismiss' the keyboard when
using an external keyboard.

\- Custom keyboard. You might build a custom keyboard for your app. Connecting
an external one will not show your custom keyboard. You'll need to ensure that
functionality is still provided when an external keyboard is connected.

There are a few other things like making sure your keyboard view resizing code
is robust enough to handle all the possible state transitions ("no input ->
software input -> bluetooth input", or "no input -> bluetooth input ->
software input", and so on).

If you're just using a standard text view you probably don't need to do
anything special. But in this case Tydlig seems to do a lot of special stuff
and probably required a bit of extra work to get Bluetooth keyboards running
without issue.

------
oliwary
I love it! Great design and should be very flexible to create simple functions
through linked numbers.

Is it really a good idea to allow 96 + 15% though (at 0:45)? Might cause some
problems for people learning maths, as it won't work on normal calculators and
doesn't really make it obvious what percentages actually are.

~~~
HCIdivision17
The New Old Thing has an article on this topic [1]. Personally, I avoid ever
using the percent button simply because I can never remember exactly how it
will behave.

[1]
[http://blogs.msdn.com/b/oldnewthing/archive/2008/01/10/70474...](http://blogs.msdn.com/b/oldnewthing/archive/2008/01/10/7047497.aspx)

------
bukka
I was actually working on something really similar.
([http://i.imgur.com/w4F8ms4.gif](http://i.imgur.com/w4F8ms4.gif))

It really is true that at any moment there is probably 4 other teams working
on a similar idea as you are.

Well I will not give up. Good luck to you too!

~~~
melloclello
Dope interface, I would use that

------
jimmytidey
Can we have something other than jingly guitar music for tech videos?

------
fpp
On Android you have a choice of TI Calculator emulations

see
[https://play.google.com/store/apps/details?id=com.Bisha.TI89...](https://play.google.com/store/apps/details?id=com.Bisha.TI89Emu)

or

[http://www.androidpolice.com/2012/02/15/nostalgia-
ti-89-calc...](http://www.androidpolice.com/2012/02/15/nostalgia-
ti-89-calculator-emulator-finally-comes-to-android-download-it-while-you-
still-can/)

------
sifarat
Handsdown it has pretty good ui. But i regret buying it, because i can't
calculate % seriously why isn't on the front. I have to press folder button to
find it.

additionally, I am baffled why do i have to press = to find end result, it
should automatically calculate as i enter figure just like my $3 citizen
calculator does.

------
jweir
So I bought it

Here are my thoughts as I use it (I will add to this comment. Hopefully the
kids won't wake up soon.)

Wish there was an UNDO. I just moved a number and didn't want too. Shake to
UNDO?

Pinch to zoom in and out. I'm using this on an iPhone.

Can I save a canvas? It doesn't look like, but maybe I'm missing it.

------
userbinator
This looks closer to Mathematica/Maple/MATLAB than a basic calculator,
although still nowhere near the power of those.

Of course 1/0 should be +Infinity, not ?...

(Disclaimer: I have a Mathematica console always open on my desktop, and
regularly use it for all kinds of calculations.)

~~~
cycrutchfield
Why should 1/0 be +Infinity? Think of 1/x at the limit as x->0 from the left
and from the right

~~~
chinpokomon
I still think the 1/0 problem can be solved if we step outside Euclidian
geometry. It is undefined for the very reason you give. The Numberphile
YouTube channel has an excellent video [1] discussing why x/0 is undefined and
worth watching.

[1]
[https://www.youtube.com/watch?v=BRRolKTlF6Q](https://www.youtube.com/watch?v=BRRolKTlF6Q)

------
cdcarter
This looks great, for some uses, but I know myself (and a lot of my coworkers)
would much prefer a beautiful iPhone calculator that behaves more like a
10-key/adding machine than an iPython notebook.

------
karlshea
Seems sort of like a slicker Soulver, I'm going to give it a shot.

------
protomyth
This looks very nice, and I'll probably buy it and Scalar this week, but it
did get me to wondering. It would be interesting to see how an APL app would
fair these days.

------
songgao
Nice work! Would be nice to have more tips on graphing. I spent 10 minutes and
still can't figure out how to do graphs. The video on website is pretty
helpful though.

~~~
songgao
Never mind... The video is in intro guide!

------
daturkel
Just a heads up, the inverse hyperbolic trig functions are arsinh, arcosh, and
artanh. That's "ar" and not "arc" which stands for area.

------
acqq
Which number system does it use? 8-byte doubles or its own library? What are
the ranges? On which libraries is it based? Does it have complex numbers?

------
zschallz
Very cool. Unfortunately, I think the price point is a bit too high (at least
for me).

~~~
pazimzadeh
$5 for a calculator with updateable functionality?

------
kangax
It would be fun to build this as a webapp in JS + canvas/SVG.

------
snambi
excellent new idea.

------
pranayairan
beautiful

------
anilshanbhag
I would just a ipython console Gone is the age of calculator

