For the Vertical Rect Series, the documentation notes that the x coordinate marks the left-side of the rect, and the x0 coordinate is the right side. However, this is actually the opposite - x0 is the starting position of the bar, and x is the ending. Even the example dataset provided doesn't work -- it renders some nonsensical graph.

On the arguments for the Rect series, it states that they're all optional, but they're only optional when you don't pass in any parameters. If you pass in a bunch of x0's but no x's for your dataset, the graph breaks because it expects an endpoint. If you pass in a bunch of x's with no x0's, the graph simply fills the entire drawing area with no regard to the Y. The meaning of these should be made more explicit.

There's absolutely no mention of xDomain/yDomain's purpose in the documentation, even though the attribute itself appears many times across different examples. While it's meaning is trivial to derive, the fact that it's missing from the docs makes it hard to figure out exactly what it's doing along with possible optional parameters, unless you drill into the code.

On the Bar Series page, the "View Code" link for the Vertical Bar Chart takes you to the code for the line chart.