I’ve been wanting to do this for a long time, but I’ve only gotten around to it now. I’ll be reviewing 4 graphing calculator apps: WolframAlpha ($1.99), GraphingCalculator ($1.99), PocketCAS Pro ($4.99), and SpaceTime ($19.99) [iTunes Links].
Usage is very simple: just type in the equation in the search bar at the top and press enter. A page will pop up with everything you could possibly want to know about the equation, including the graph, factored form, vertex, x-intercepts, etc. Graphing multiple equations at the same time is just a bit more complicated. To graph multiple equations, just put a comma between each equation.
The one thing I can’t figure out how to do is how to adjust the range of the graph, although WolframAlpha is pretty good at guessing the range. Overall, WolframAlpha is a very good graphing calculator, apart from its one major downside, the requirement of an internet connection. You can try the free desktop version of WolframAlpha over at http://www.wolframalpha.com.
First, I’d like to give some props to the developer of this app for being the first to respond to my emails. He responded in under 40 minutes with the promo code. I assume that the developer will respond just as quickly to support queries.
In terms of the actual app, the interface is nothing special. At the bottom of the screen there is a toolbar with Calculator, Equations, Graph, Table, and More. The bottom half of the Calculator screen has normal calculator buttons, and at the top there is a scrolling history of all the equations entered. On the Equations screen, there is y1 – y4 to enter in 4 equations for the Graph and Table tabs. While I’d like some more equations, 4 is fine for most equations at the moment.
The Graph tab is very simple; it displays the graph. Tracing is more interesting. Double-tap the screen and you get options for normal tracing and two snapping tracing modes. The Table tab is even simpler; it just shows the table with the equations. The edit button changes the table start and table delta.
The final tab, More…, has Help and Settings. Help is rather self-explanatory, and Settings has settings for all the tabs. This includes options such as the background color for the keyboard and the mode of graphing.
PocketCAS is certainly not your usual graphing calculator. When you first start PocketCAS, a tutorial document will come up. Tap Menu, and then New Document to clear the tutorial. You’ll see an empty document. Tap ‘New Calculation’ to start entering a new calculation. To graph, enter in equations (without the y= part), pressing Enter after each one. PocketCAS could theoretically graph an infinite number of equations. To graph, tap the Plot button.
To solve normal equations, open a calculation or create a new one, type the equation(s) and press Go. PocketCAS will go back to the main screen and below the original equation(s) is the answer. As I said earlier, PocketCAS is not your usual graphing calculator app. The function to create and save documents works kind of like a programming function, allowing you to pre-insert long equations like the quadratic formula (though there are apps that just do the quadratic formula). Overall, PocketCAS is a really good graphing calculator for $5, though unless you really want the interface, get myCalculator for 4 dollars.
This app is the most expensive one at 20 dollars, but I think it’s worth it if you need advanced calculations or a programming method. It does pretty much everything I could ever want. It does all the math functions that WolframAlpha does, but doesn’t need an internet connection. This may be the most powerful app, with its 3D graphing, scroll bars to change variables, fractal generation, etc.
SpaceTime operates similarly to PocketCAS. The tutorials are especially interesting. They highlight the buttons you need to press, and let you learn by doing. I’ve found them extremely useful in learning about SpaceTime.
SpaceTime also has customizable colors, with some presets. The scripting function is probably what distinguishes this app the most. You can create proper scripts with parameters, and have the scripts do functions, perform repetitive equations, and other tasks. To use a script in another document, you have to include the script via the menu. Then you type the name of the script and what the parameters should be, press solve, and you get the equation. That’s the main functions.
Overall, SpaceTime is the most powerful app, though at 20 dollars each for iphone and iPad versions the price is a bit steep. If you prefer a more “traditional” interface and don’t need the advanced functions, get myCalculator Pro, by the same developer, which for $4 works on both iPod and iPad and does most of the graphing that SpaceTime does. Also, if you really like fractals, try Fractals, again, by the same developers
So, after trying out the graphing calculator apps, SpaceTime and myCalculator Pro are my favorite apps. If you’re looking for a good graphing calculator, go get one of them and graph away.