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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

#141

Post by ketralnis »

peterhajas wrote: post #115
Lazare wrote: post #59

Earlier quoted context omitted.

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

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.

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.

Re: Tydlig – Calculator Reimagined for iPad and iPhone

#143

Post by k-mcgrady »

visakanv wrote: post #136
k-mcgrady wrote: post #61

Earlier quoted context omitted.

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?

I'd suggest that they do what we do when we don't have the resources we need in the 'real world'- figure out some way to collaborate with others!

Collaborate during a test? That usually leads to cheating. It would also likely disadvantage the person they are working with who now has to share resources. Not to mention the fact that if this person doesn't own an iPhone they either won't know how to use it or won't be quick at using it slowing them down (bad in an exam situation). The students who do own iPhones will be faster and will be better because they are more experienced with the tools - not because they are better students.

Re: Tydlig – Calculator Reimagined for iPad and iPhone

#144

Post by InclinedPlane »

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 just have an HP48 emulator on my android phone. It's pretty sweet actually.

Re: Tydlig – Calculator Reimagined for iPad and iPhone

#145

Post by csmuk »

jwr wrote: post #123
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…

Couldn't agree more. I regularly use a HP12c, HP48 and HP50G. However, the emulators for all of those are really quite good (for hp12c, get the one from RLM Tools), especially when ran full-size on an iPad. I am glad to see this effort because we really need some innovation in the world of calculators. The science of making them has stagnated in the late 1990s. HP50G isn't really different from HP48, first introduced…

To be fair both HP and TI have tried their best to do something better than their older lines but it's resulted in the following:

http://www8.hp.com/us/en/products/calculators/product-detail...

I've used the emulator, but it's less productive than the 50g. Also TI's nSpire offering is just horrid.

I don't use my calculator in education which means I'm completely forgotten.

Re: Tydlig – Calculator Reimagined for iPad and iPhone

#146

Post by csmuk »

chinpokomon wrote: post #135
csmuk wrote: post #83

Earlier quoted context omitted.

Spot on. This is one reason I still use my 50g - it uses decimal internal representation with known precision on every operation. Casios are a mess. They are actually made my Kinpo which do a shitty job of pretty much everything. The notable exceptions being the FX991MS and Fx5800P which are very very close to my 50g (which was laboriously tested on paper before I trusted it)

I favor the 48GX with several modifications. I have a library that gives me 5 stack lines, but also shows a symbolic representation. In other words, typing "5 6 /" is represented as "5/6" rather than a decimal equivalent. If you multiply that by 2, my calculator maintains the symbolic representation as "(5/6)*2". By retaining values as symbolic representation for as long as possible, when you finally evaluate, it wil…

The 50g already does that as it has a built in CAS so symbolic is default. This are represented in their rational form or with respect to pi.

50g is basically a 48GX emulator with 400MHz ARM core that emulates Saturn, MetaKernel and a CAS. Goes like lightning. Oh and a bigger screen so you get 7-9 stack lines. Also you can use SD cards as ports. Mine has 256Mb of Flash. Eats a set of batteries once a month but it's worth it for the power.

I can create a symbolic list with 50,000 entries in quite happily on the device then do all standard two-variable stats on it in 1-2 seconds.

Re: Tydlig – Calculator Reimagined for iPad and iPhone

#147

Post by melloclello »

bukka wrote: post #127

I was actually working on something really similar. ( 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!

Dope interface, I would use that

Re: Tydlig – Calculator Reimagined for iPad and iPhone

#148

Post by ygra »

smikhanov wrote: post #107
rooster8 wrote: post #91

Earlier quoted context omitted.

I'd love to hear you highlight a few of the unexpected challenges.

For example: 1. When someone enters "1 / 3" how many decimal places you display in the result? My approach: use MAX(4, MAX(decimal_places(entered_values))). His approach: use 3 everywhere. - Bonus 1: how many decimal places you display when someone enters "sin(3.14)"? What about "sin(1 / 3)"? My approach: use as much space you have on the screen. - Bonus 2: how do decimal places propagate when you're using refs? 2. W…

More to the point, I guess: UX is hard ;-)

The switching to scientific notation around x · 10¹⁶ hints at using IEEE 754 doubles underneath. I wonder what they are using underneath for the math functions (they make it sound like it's custom-built). I spent a while in uni porting math function implementations from C to Java for a simulations framework and noticed that they usually all have the same pattern of selecting many different ways of calculating the result based on the intervals of the operands (to more or less guarantee 15 digits of precision instead of 0–15 as would otherwise be the case).

Re: Tydlig – Calculator Reimagined for iPad and iPhone

#149

Post by ygra »

k-mcgrady wrote: post #143
visakanv wrote: post #136

Earlier quoted context omitted.

I'd suggest that they do what we do when we don't have the resources we need in the 'real world'- figure out some way to collaborate with others!

Collaborate during a test? That usually leads to cheating. It would also likely disadvantage the person they are working with who now has to share resources. Not to mention the fact that if this person doesn't own an iPhone they either won't know how to use it or won't be quick at using it slowing them down (bad in an exam situation). The students who do own iPhones will be faster and will be better because they are…

Not necessarily, although it might be difficult for math tests.

In school we had one larger test in German where the teacher left us alone for 4 hours. What I noticed was that we did collaborate to some extent – we shared and discussed ideas. But since we had to write an essay with our interpretation of some piece of literature there wasn't much possibility of "cheating" per se. Simply copying the text from another would not work and copying their ideas outright wouldn't either. And to get at least something of decent length there wasn't the option of fooling around for three hours either. Granted, this was in 11th grade, so we were a bit older already. It may well fail spectacularly in other environments. The teacher knew us for a few years and trusted us, and it worked out.

Re: Tydlig – Calculator Reimagined for iPad and iPhone

#150

Post by tbirdz »

jbri wrote: post #60
lowboy wrote: post #53

Earlier quoted context omitted.

> 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…

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…

>"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.

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