# Brownian Motion Using Google Visualization API and R

### Yihui Xie / 2008-11-05

Yesterday I took a look at the Google APIs for visualization; the gallery is poor for data visualization, I think. Anyway, an idea came to my mind – to make use of the MotionChart to demonstrate the Brownian Motion. Random numbers can be generated from R and read into JavaScript (the `DataTable` object in Google API). Here is an example:

``````<script type="text/javascript" src="http://www.google.com/jsapi"></script>
<script type="text/javascript">
function drawChart() {
data.setValue(0, 0, "01");
data.setValue(0, 1, 1901);
data.setValue(0, 2, 1.24);
data.setValue(0, 3, -0.37);
data.setValue(1, 0, "02");
data.setValue(1, 1, 1901);
data.setValue(1, 2, 0.12);
data.setValue(1, 3, 0.48);
data.setValue(2, 0, "03");
data.setValue(2, 1, 1901);
data.setValue(2, 2, -1.5);
data.setValue(2, 3, -1.21);
....
data.setValue(748, 0, "14");
data.setValue(748, 1, 1950);
data.setValue(748, 2, 1.73);
data.setValue(748, 3, -2.24);
data.setValue(749, 0, "15");
data.setValue(749, 1, 1950);
data.setValue(749, 2, 2.38);
data.setValue(749, 3, 16.65);
chart.draw(data, {width: 600, height: 500});", "      }
</script>

<div id="chart_div" style="width: 600px; height: 500px;"></div>
``````

I have added the R function `g.brownian.motion()` to the animation package.