Showcase Review: Pi Cubed, a visual math application for iPhone / iPod Touch
In 'Showcase' reviews, the reviewer is the developer. No claim of objectivity is made, but it’s a chance for the developer to show off his/her app. Here, Brad Larson presents Pi Cubed. You may also remember Brad Larson as the developer of Molecules, a molecule visualization application for the iPhone.
Pi Cubed is a visual math application for iPhone / iPod Touch, available now on the App Store for $9.99 (or the local equivalent). Unlike traditional calculators that use fixed buttons and a small numerical display, Pi Cubed uses the entire screen to typeset and evaluate calculations as you enter them. Input and editing operations are all designed around touch interactions, and Core Animation is used to fluidly animate the entire interface. Calculations can be stored to and retrieved from an internal database, a database that also contains over 150 preprogrammed equations from a variety of fields. Overall, Pi Cubed provides a way of doing math on the go which breaks with interface conventions that have been around since the invention of the calculator.
Touch-based calculation entry
The central purpose of Pi Cubed is to perform calculations as you would on a piece of paper. The main display is focused on an equation, with the typeset calculation on the left and the result on the right.
A sample calculation
To enter a calculation, you select a mathematical operation from the menus on the bottom of the screen. Supported operations include:
- Arithmetic
- Exponents
- Logarithms, including ones with arbitrary bases
- Square and arbitrary roots
- Trigonometry (sin, cos, tan), including hyperbolic and inverse variants
- Parentheses and brackets
- Constants
- The error function
- Factorials
When all blanks in a calculation have been filled in with numbers, the result of that calculation will be immediately displayed. Any changes to the calculation will be reflected in real time.
Unwanted elements in your calculation can be deleted by simply tapping on the item and touching the small X in its upper left corner.
All entry and editing operations are fully animated. This is difficult to express in words and screenshots, so I recommend that you watch the walkthrough video on the application's page.
Quick calculation saving and retrieval
You can store any calculation for later retrieval and editing simply by tapping on one button. These calculations are archived in chronological order within a built-in database.
A listing of recent calculations
You can load any of these calculations by pulling up the listing of them and simply tapping on the one you want to retrieve. A small representation of the calculation is present in the list as a quick reminder of what you were doing. Calculations can be easily deleted when you no longer wish to have them around.
Over 150 built-in equations
In addition to your own saved calculations, over 150 equations are included with Pi Cubed. These equations cover a variety of fields, many of them engineering-related (I'm a chemical engineer by training, so my references tended to lean in that direction). I plan to add many more, and am open to suggestions.
Some of the categories of equations in the built-in database
You can choose an equation from one of the categories by its description or thumbnail preview.
A list of equations covering a specific field
A retrieved equation will replace your current calculation (you have the option of saving your calculation first). All variables are fully annotated, meaning that if you tap on one, a text label containing its description will appear. This aspect of the application alone can be extremely useful to students or scientists as a reference.
An equation loaded from the database, showing an annotated variable
However, these equations can also be numerically evaluated. By tapping on each variable and filling in a value, you will be presented with the calculated result of that equation, in the same manner as the calculations you built from scratch.
LaTeX equation export
If you would like to use one of your typeset equations or calculations in a publication, Pi Cubed has the ability to export a LaTeX representation of the current expression via email. You (or another recipient of the email) can then copy and paste the LaTeX code from the mail message into a LaTeX document for typesetting.
In-application manual
Pi Cubed is a reasonably complex application for a handheld, so a full manual in HTML is located within the application itself. This manual includes walkthroughs of all common operations, along with a full reference for each program feature.
A page from the in-application manual
Planned future additions
This is just the start for Pi Cubed. I have some significant plans for the application, including:
- Even more equations for the built-in library
- Matrix math
- Unit support for numbers (ex: 2 in + 1 ft = 0.3556 m)
- A Mac desktop client that pairs with the iPhone application
Additionally, several of the new features in the pending iPhone 3.0 firmware update will be used to extend the capabilities already present in the application, or even add new ones.
Final words
Pi Cubed handles calculations in a very different way from your standard calculators, by relying on a touch-oriented visual presentation of the math involved. This may not appeal to all people, for whom a product like the excellent PCalc may be a better solution. Personally, by combining this with a graphing application like Grafly I have been able to finally discard my old TI-85 for my day-to-day work. I also know that the college version of me would have loved to have the equation library handy for some of those engineering exams.
Acknowledgments
I'd like to once again thank Drew McCormack and MacResearch for the exposure they provided for Molecules, my previous iPhone / iPod touch application. By all rights, a 3-D molecular visualizer should have only reached a niche audience, but Molecules was the eighth-most downloaded free utility in the 2008 App Store rankings (behind two flashlights, of course), reaching over 360,000 users. This encouraged me to try something a little more ambitious, that being Pi Cubed.
Finally, I'd like to thank my beta testers, several of whom came to me via MacResearch. Their feedback has proven invaluable during the development of this application. I can fit in a few more testers for future versions of Pi Cubed. If you are interested in being a tester, or if you have any other feedback on the application, please feel free to send me an email at contact@sunsetlakesoftware.com. Support for Pi Cubed is also provided via the product's forums on my site.
Comments
Well done!
Just bought a copy, extremely sweet! It's also a great example of how with core animation adds a lot of polish and creates a very smooth and elegant UI.