A stream graph, is a type of stacked area graph which is displaced around a central axis, resulting in a flowing, organic shape.
Stream graphs display the changes in data over time of different categories through the use of flowing, organic shapes that somewhat resemble a river-like stream. This makes Stream Graphs aesthetically pleasing and more engaging to look at.
In a Stream graph, the size of each individual stream shape is proportional to the values in each category. The axis that a Stream Graph flows parallel to, is used for the time scale.
Stream graphs are ideal for displaying high-volume datasets, in-order to discover trends and patterns over time across a wide range of categories.
This is an open source visual. Get the code from GitHub: https://github.com/Microsoft/powerbi-visuals-streamgraph