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Tydlig – Calculator Reimagined for iPad and iPhone

tydligapp.com

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Re: Tydlig – Calculator Reimagined for iPad and iPhone

#61

Post by k-mcgrady »

visakanv wrote: post #42
tolmasky wrote: post #26

Earlier quoted context omitted.

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.

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. :(

What about the kids without iPhones? Are they handicapped because they can't afford one? Or is the school expected to provide hundreds of iPhones?

Re: Tydlig – Calculator Reimagined for iPad and iPhone

#62

Post by Someone »

jckt wrote: post #4

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 g…

"It's not like a graphing calculator app is going to be that difficult to program"

It is surprisingly hard to get something that produces reliable plots. It starts with getting something as simple as sin(1/x) or x/(x^2 + 5x + 1) to plot reasonably well, and gets harder from there soon (edit: if you want to complicate things, pick a function that is only defined on some numbers, such as sqrt(x^2 * sin(x^3 - x). Adding a pair of || around subexpressions also complicates things)

For example, at https://www.desmos.com/calculator (one of the top results from a google search) zooming in on sin(1/x) shows a plot that sometimes doesn't go up to 1.0 for values of x close to zero. Its plot is decent, but deceiving.

And you will have to do those well, as the target audience of students encounters such functions every day.

And the Mac OS X one is Grapher (http://en.wikipedia.org/wiki/Grapher)

Re: Tydlig – Calculator Reimagined for iPad and iPhone

#63

Post by zimbatm »

withad wrote: post #51
visakanv wrote: post #42

Earlier quoted context omitted.

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. :(

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 i…

It probably depends on the subject but if they don't have that basic knowledge they're not going to be effective filling in the test either, even with Google it always takes longer.

Ideally tests should check the deeper understanding of the student and not just his memory skills. In that case Internet access is also not a problem.

Re: Tydlig – Calculator Reimagined for iPad and iPhone

#64

Post by pascal_cuoq »

melloclello wrote: post #28
csmuk wrote: post #15

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…

I'm working on an RPN calculator (with some pretty sweet gestural functionality) which solves approximately half of those problems. Wait, no, more like a quarter. Welp. It does return the correct value for sin(π) though (you gotta call __sinpi(x / M_PI) if you don't want to return -8.74e-8 or some ridiculous value).

> It does return the correct value for sin(π) though (you gotta call __sinpi(x / M_PI) if you don't want to return -8.74e-8 or some ridiculous value).

This is ridiculous. Your calculator (most calculators) cannot apply sin to π, because π is not representable is their system (typically base-2 or base-10 floating-point).

What you have done here is make sine worse for all values, including the representable value closest to π, in order to obtain what you think is a cosmetically satisfying result for the latter. Note that seeing the closest representable value to π does not mean that the user intended π. Perhaps the user obtained this value as the result of a computation and it's a coincidence. Or perhaps the user really wants to know what the sine of 0x1.921fb54442d18p+1 (the double closest to π) is. Hint: it is not zero.

Re: Tydlig – Calculator Reimagined for iPad and iPhone

#65

Post by 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!

Re: Tydlig – Calculator Reimagined for iPad and iPhone

#66

Post by csmuk »

pascal_cuoq wrote: post #64
melloclello wrote: post #28

Earlier quoted context omitted.

I'm working on an RPN calculator (with some pretty sweet gestural functionality) which solves approximately half of those problems. Wait, no, more like a quarter. Welp. It does return the correct value for sin(π) though (you gotta call __sinpi(x / M_PI) if you don't want to return -8.74e-8 or some ridiculous value).

> It does return the correct value for sin(π) though (you gotta call __sinpi(x / M_PI) if you don't want to return -8.74e-8 or some ridiculous value). This is ridiculous. Your calculator (most calculators) cannot apply sin to π, because π is not representable is their system (typically base-2 or base-10 floating-point). What you have done here is make sine worse for all values, including the representable value close…

Nailed it. Nice to see someone who understands the situation properly.

Re: Tydlig – Calculator Reimagined for iPad and iPhone

#67

Post by fophillips »

burriko wrote: post #52
asselinpaul wrote: post #47

Earlier quoted context omitted.

I am currently in Year 13 in London. You are definitely allowed TI in the mathematics exams (A-Levels). TI-89 is one of the only that is banned because of its CAS. Friends in the French system are allowed the TI 89 though.

Yep, I did Maths A-level in the UK back in the 90s, and a TI graphing calculator was basically a requirement for the exams.

Interesting, I wasn't allowed to use one in A-Levels or university exams.

Re: Tydlig – Calculator Reimagined for iPad and iPhone

#68

Post by smikhanov »

Great to see more people attacking the underserved math app segment on the iOS.

I'm the author of Scalar (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!

Re: Tydlig – Calculator Reimagined for iPad and iPhone

#69

Post by VLM »

csmuk wrote: post #15

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…

In same boat as you. Don't laugh too loud but most of my "math" work is done via ssh (and ssh app on phone) and running octave or R on gigantic datasets.

I went thru the same annoyance on my phone/tablet and although I have droid48, free42, and hc-16C on my android devices I mostly just ssh into a real machine.

I have toyed with the idea of graphical environments like mathematica/maple on a real machine via rdesktop/vnc on my tablet, but I don't do CAS so much as stats where I stick with R anyway. And those apps cost lots of money for something I don't do much of anyway.

Eventually with any problem, either you solve it or reach an event horizon where the UI is too horrific to use anymore. So when I can no longer handle the touch screen keyboard I just disconnect from the screen session (yeah, yeah, I know kids these days use tmux) and reconnect on a real computer complete with keyboard and big display.

For medium sized arithmetic problems (as opposed to math problems), just use google drive's spreadsheet and then I can access it anywhere in the world on any kind of machine I have access to. So that's where "total of this column vs total of that column" level of problems live.

An add on android keyboard built specifically for math, or more specifically for R or octave, would be interesting.

Re: Tydlig – Calculator Reimagined for iPad and iPhone

#70

Post by ronaldx »

pascal_cuoq wrote: post #64
melloclello wrote: post #28

Earlier quoted context omitted.

I'm working on an RPN calculator (with some pretty sweet gestural functionality) which solves approximately half of those problems. Wait, no, more like a quarter. Welp. It does return the correct value for sin(π) though (you gotta call __sinpi(x / M_PI) if you don't want to return -8.74e-8 or some ridiculous value).

> It does return the correct value for sin(π) though (you gotta call __sinpi(x / M_PI) if you don't want to return -8.74e-8 or some ridiculous value). This is ridiculous. Your calculator (most calculators) cannot apply sin to π, because π is not representable is their system (typically base-2 or base-10 floating-point). What you have done here is make sine worse for all values, including the representable value close…

> because π is not representable is their system (typically base-2 or base-10 floating-point).

Casio scientific calculators do have an internal representation of π (it's treated differently from the closest possible typed value) and very nuanced representations of numbers in general.

As you say, this is where calculator apps almost inevitably fail - representing numbers properly is really crucial to the UX, and floating point numbers are not sufficient.

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