A Streamgraph is a more unusual type of graph. It shows the way that a set of numbers has changed over time by their relative area. (See the sidebar for the history of Streamgraphs).
A streamgraph is based on a rectangle of data: in this example, "Comedy" had a volume of 10 in 2008, and of 12 in 2010.
Once you have the app installed, you can press "Generate" to get sample data that is appropriately formatted.
There are two buttons to specify the chart data. Press "Series Values..." to select the data that represents the values of the dataset, including the column headers. In the table below, those are italicized.
Press "Horizontal axis labels..." to select the data that represents the column names. In this example, you would select the boldfaced years.
All of the values in the table should be numbers greater than zero. If the application sees a number less than zero, it will replace it with a zero.