Graphing Calculator

Version 1.2.0

• Redesigned the keyboard so it can slide horizontally for the commonly used functions. (iOS 4.x and higher only)
• The editor uses Apple’s standard text view. This means you can now move the cursor with your finger, and it supports copy/paste. The arrow keys were removed from the keyboard. (iOS 4.x and higher only)
• Added VGA output. This feature requires that you have an iPhone4, a 4th generation iPod Touch or an iPad. Earlier devices do not support Apple’s VGA adapter.
• Fixed a bug in the acsc() function, which caused it to return “syntax error”.
• Fixed a bug responsible disabling the “edit” button on the equation’s tab.

Version 1.2.1

This update fixes bugs that were introduced in the 1.2.0 update. No new features were added.

• Changed the equation editor so that moving the cursor is easier. The magnifying glass shouldn’t be covered by the user’s finger anymore.
• Fixed a bug responsible for the equation editor keyboard to stick around after editing an equation.
• Fixed a bug in evaluating user functions on the calculator screen.
• When pressing the open parenthesis key, the app will automatically place a multiplication sign after numbers or variables.

A few people asked why the updated keyboard is not supported on firmware 3.x. In order to use Apple’s standard UITextView along with a custom keyboard, I had to make use of an API that was introduced in SDK 3.2. Since the iPhone and iPod went from 3.1 directly to 4.0, I had to restrict the new keyboard to devices running 4.x or higher. Of course the old keyboard will continue to work on devices running firmware 3.x.

Version 1.1.10 for the iPhone/iPod, and version 1.0.2 for the iPad was approved by Apple last week. Right now, I’m only supporting video output on the iPad version of the application. Here are the release notes:

Version 1.1.10 (iPhone/iPod Touch)

• Fixed a sampling problem that resulted in vertical portions of graphs not being drawn.
• Improved the root/intersection finding algorithm.
• Added a proportional zoom option.
• Fixed a problem related to the “ans” key.
• Calculator history is now saved when you quit the app on iOS4.
• Fixed several minor bugs that people found since the last update. I would like to thank everyone that e-mailed me.

Version 1.0.2 (iPad)

• Everything you see listed for version 1.1.10 of the iPhone/iPod app.
• Added video output support, which was requested by several teachers. You can now connect the iPad to an external monitor in order to display the graph view.
• Added a left-handed keyboard layout option that repositions the number pad.

A feature that quite a few teachers requested recently is VGA output, so that they can display the graphs on a projector or TV. Actually, many people asked for this over a year ago as well, but there was no public API available in the iOS SDK. With the introduction of the iPad, Apple enabled developers to make this happen, and I will be supporting it in the next release. It will be available in both the iPhone and the iPad version of the calculator, and you’ll be able to use any of the video cables (component, VGA, or RCA). The 2G and 3G iPhones will not support it because of performance issues, so you’ll need at least an iPhone 3GS.

Video Output

Last week, I released a new version of the Graphing Calculator for the iPhone (version 1.1.9). It’s got the following changes:

• Fixed a bug responsible for crashing the application on iOS 4.
• Multitasking support that allows you to jump back to where you left off (only using iOS 4).
• Updated the graph logic, buttons and icons to look great on the new retina display.
• Changed the keyboard’s click sound to match Apple’s default keyboard.
• Fixed a problem with the nPr() function.
• Corrected an issue with gamma() and lgamma().

I had a good idea what my graphs would look like on the new retina display, but seeing it person was still shocking. I can not see the individual pixels that make up curves, which looks great. I would like to see a display with a similar pixel density for the iPad.

Earlier this week, Apple approved the iPad version of the Graphing Calculator, and it’s now available for download. This first version matches the feature set of the iPhone application, but it’s easier to use. The GUI was rewritten from the ground up to take advantage of the iPad’s bigger screen.

iPad Screen Shot