The Expressions Cheat Sheet

The sine wave function is a friend of yours that gives you back a number between -1 and 1.

``````Math.sin() // a number between -1 and 1
``````

The exact results depends on you. Unfortunately, it expects you to give it a number between 0 and 6.2831.
Wait a minute. That's very specific. 6.2831?
Well it turns out 6.2831 is exactly 2PI, which is the point in which the sine wave results in exactly one lap.

Before you panic, try the examples below:

### Rotation

Apply this code to a Rotation property:

`````` 45 * Math.sin(Math.PI * 2  * time) // gets a number between 0 and 1, then multiplies it by 45 degrees;
``````

With a single line of code, we got your layer to rotate 45 degrees back and forth every second. How cool is that?

We are multiplying 2PI with the current time.
When the time is 0 seconds, we are 0 laps into our sine wave. When time is 1 second, we are 1 exactly one lap into our sine wave. And this goes on forever.
This helped us get a number that fluctuates between 0 and 1 repeatedly. We then multiplied it by 45 and got a number between -45 and 45. That's awesome!
The Rotation property expects a number, and a number between -45 and 45 is a number, so we did a good job on that!

For our final expression, we can do something like this:

``````var loopDuration = 5; // every 5 seconds, or however many seconds you decide
var degrees = 45; // or however many degrees you want
degrees * Math.sin(  Math.PI * 2  * time / loopDuration);
``````

Now we can easily change the value of"loopDuration" in order to determine the duration of one, full lap. This makes for an easy and comfortable sine wave experience!

Coming Soon...