basemap: sets the base map. The map definitions must follow the TopoJSON format and if saved in Wikipedia are available for this module. Maps in the default directory Special:Prefixindex/Template:Graph:Map/Inner/ like Worldmap2c-json should only be referenced by their name while omitting the Module:Graph/ prefix to allow better portability. The parameter also accepts URLs, e.g. maps from other Wikipedia versions (the link should follow the scheme of //en.wiki.x.io/w/index.php?title=mapname&action=raw, i.e. protocol-relative without leading http/s and a trailing action=raw to fetch the raw content only). URLs to maps on external sites should be avoided for the sake of link stability, performance, security, and she be assumed to be blocked by the software or browser anyway.
scale: the scaling factor of the map (default: 100)
center: map center (corresponds in the map data to both comma-separated values of the scale field)
feature: which geographic objects should be displayed (corresponds in the map data to the name of the field under the objects field). The default is value countries.
ids of geographic entities: The actual parameter names depend on the base map and the selected feature. For example, for the above mentioned world map the ids are ISO country codes. The values can be either colors or numbers in case the geographic entities should be associated with numeric data: DE=lightblue marks Germany in light blue color, and DE=80.6 assigns Germany the value 80.6 (population in millions). In the latter case, the actual color depends on the following parameters.
colorScale: the color palette to use for the color scale. The palette must be provided as a comma-separated list of color values. The color values must be given either as #rgb/#rrggbb or by a CSS color name. Instead of a list, the built-in color palettes category10 and category20 can also be used.
scaleType: supported values are linear for a linear mapping between the data values and the color scale, log for a log mapping, pow for a power mapping (the exponent can be provided as pow 0.5), sqrt for a square-root mapping, and quantize for a quantized scale, i.e. the data is grouped in as many classes as the color palette has colors.
domainMin: lower boundary of the data values, i.e. smaller data values are mapped to the lower boundary
domainMax: upper boundary of the data values, i.e. larger data values are mapped to the upper boundary
legend: show color legend (does not work with quantize)
defaultValue: default value for unused geographic entities. In case the id values are colors the default value is silver, in case of numbers it is 0.
Note: In the editor preview the graph extension creates a canvas element with vector graphics. However, when saving the page a PNG raster graphics is generated instead.
