This looks interesting, but I can't see myself using it on an ipad or phone. This is something I'd want to use on a desktop, with a keyboard, while multitasking with other programs.<p>Edit: I'll keep it in the back of my head, and I might try it later.
Looks like an interesting halfway house between a text editor and a full-blown CAS like Mathematica (since I have a license, that's what I use as a scratchpad for this kind of thing). It also seems to overlap with Soulver, which is my go-to calculator on iOS.<p>Cleverly, Calca appears to go a bit further than even MMA by back-filling changed definitions, almost like functional reactive programming. This is neat and something I've wanted to see for a long time.<p>I'll be buying once I get home to my iPad, but I really want to see the Mac OS version!
Glad to see Soulver [1] has some competition.<p>[1] <a href="http://www.acqualia.com/soulver/" rel="nofollow">http://www.acqualia.com/soulver/</a>
It would be really neat if you could tap a number and drag it left or or right to adjust it's value. Everything would recalculate and you could have a small dialog box out to the side to adjust the increment level of the 'drag adjustment'. An iPhone screen probably wouldn't have room for the dialog box so you could putting it in settings but for iPad it would fit just fine.
I certainly can't speak for others, but my typical use case is projected to be in meetings. Imagine sitting in a room with a bunch of engineers and managers, and someone says something worth checking the math on.<p>If you're not the lucky dude at the conference room's computer and just happens to have IPython Notebook/LightTable/Excel/`w/e`, then this will be handy. Be the guy who keeps up with the conversation <i>and</i> can check assumptions.<p>The fact it allows variable names with spaces is just the sweetest syntactic sugar.<p>It runs a smidge slow on the iPhone, but since that's the tool I have on hand, I'll gladly take a lightweight equation solver like this. (And if the slide-to-change numbers feature gets added, I'll <i>happily</i> buy it again. Twice.)
Looks reasonable.<p>However you'll have to prize my HP 50g calculator out of my cold dead hands before I'll mix mathematics and a touch screen.
A few suggestions, since the author seems to be hanging around in this thread:<p>It would be good if plurals for variable names were the same as the singular, so that<p>light speed = 299,792,458 meters/second<p>Would be compatible with<p>time to earth=> 499.242173411seconds<p>Also, it would be nice if "per" was equivalent to /<p>Also, it would be nice if definitions didn't have to be<p>Single item on the left = many things on the right. For example, this would be nice:<p>Miles per gallon = 34
Gas tank = 13 gallons
Range = miles per gas tank<p>So far I'm having a lot of fun and already posted it to Facebook.
Is there anything like this for stats? I remember watching my then girlfriend in the throes of her thesis, having to tweak and re-run a Stata script again and again and again.<p>Also, for seriously complicated work, maybe a desktop all in one touch screen could be useful, so long as it's oriented more horizontally than vertically.
In the Introduction, under functions:<p><pre><code> f = m*a
f(20) = 20a
</code></pre>
Which is ok, but then farther down:<p><pre><code> f(a) = m*a
f(20) => 20a
</code></pre>
This seems incorrect, since I was expecting m*20. On a separate page, this seems to work fine, though.<p>Otherwise, quite nice.
I like it, going to have to start using this more and can't wait for the desktop app.<p>Just a heads up, when creating a new document in ios 7 beta 3 on the ipad there is a crash. Author, what is the best way to send you the crash log?<p>Just something to look into before ios7 releases.
Here's another take on it, albeit more for financial computations.<p>Includes a formula preview:
<a href="http://numbercanvas.com/" rel="nofollow">http://numbercanvas.com/</a>