Feature summary:

• ECharts has many chart types, of which the Charts extension only (currently) supports a few. Some notable ones from the previous Graph extension that are missing include (sub-tasks would be desirable):
  • Stacked bar charts (T373347)
    • Both uses less space than a side-by-side bar chart and better shows totals per category
  • Scatter plots (maybe possible currently but I can't find any info?)
    • This is probably the simplest to implement considering there is already a line series. Useful for graphs depicting relationships between variables.
  • Maps (choropleth, not those creatable in Kartographer)
    • Kartographer is helpful for creating detailed, interactive maps; for smaller scale choropleth maps that involve repeatable coloured in elements, the previous Graphs extension was used heavily
  • Tree diagrams
    • There are non-Graphs versions of such charts on the English Wikipedia, and I am not sure of the extent to which this type was actually used (though it was supported)
  • Timelines (T137291)
• All of the above are natively supported by ECharts.
• Charts should not seek to just be emulate what Graphs did, and so it might be worth considering some other charts, subject to use, such as sankey diagrams and treemaps.

Use case(s):

• Users are currently unable to use any of the above chart types. The first three are used very often on different Wikipedias and are currently inaccessible.

Benefits:

• At the very least, Charts should supply most of the series that Graphs previously provided. I, as a user, want to be able to use a reasonable (but not excessive) number of different data visualisations.