The reason we don’t provide sample xml for that demo is that the data source is not a standard SFDC datasource. Its a more complicated set of aggregations and summaries of sales data delivered in a few PostgreSQL tables.
The Segment by Subcategory chart is totally facilitated by the data. We do server side aggregation and calculation to produce a simple table with rows for each product (Chairs, Accessories, etc) and columns for each Subcategory (Consumer, Home Office, etc). In addition, the field value at each intersection is expressed as a percentage of the row total. (Standard Pivot table stuff). So my Skuid Chart is stupid easy.
The fun is in the data aggregation and processing. But you really shouldn’t ever do that client side anyway - if you can help it.
Sorry about not being more help. But that’s the back story on those charts and graphs.