Created a pie-chart after attending an event in SF
To use it, assuming you have polymer and bower already installed.
Import the platorm and the custom element to a html page:
<script src="platform/platform.js"></script>
<link rel="import" href="simple-pie-chart/simple-pie-chart.html">
Add the element to a page and give it some JSON to render the pie:
<simple-pie-chart size="200" lineWidth="2" slices='[{"caption": "Caption1", "color": "red", "slice": 120},
{"caption": "Caption2", "color": "#0000ff", "slice": 45},
{"caption": "Caption3", "color": "green", "slice": 0.25}]'>
The slice value can be either degrees (0 <slice <= 360) or percentage (0 < slice <= 1.0) The element (html5 canvas) use radians but I figured percentages or degrees are preferred.