Editing Cartogram (section)

== Multivariate cartograms ==
[[File:Canadian Federal Election Cartogram 2019.svg|thumb|left|upright=1.15|Hexagonal mosaic cartogram of the results of the 2019 Canadian parliamentary election, colored with the party of each winner using a nominal choropleth technique.]]
{{main | Multivariate map }}
Both area and linear cartograms adjust the base geometry of the map, but neither has any requirements for how each feature is symbolized. This means that [[Map symbol|symbology]] can be used to represent a second variable using a different type of [[Thematic map | thematic mapping technique]].<ref name="torguson2009" /> For linear cartograms, line width can be scaled as a [[flow map]] to represent a variable such as traffic volume. For area cartograms, it is very common to fill each district with a color as a [[choropleth map]]. For example, [http://worldmapper.org/ WorldMapper] has used this technique to map topics relating to global social issues, such as poverty or malnutrition; a cartogram based on total population is combined with a choropleth of a socioeconomic variable, giving readers a clear visualization of the number of people living in underprivileged conditions.

Another option for diagrammatic cartograms is to subdivide the shapes as charts (commonly a [[pie chart]]), in the same fashion often done with [[proportional symbol maps]]. This can be very effective for showing complex variables such as population composition, but can be overwhelming if there are a large number of symbols or if the individual symbols are very small.