Editing Cartogram (section)

===Mosaic cartograms===
[[File:Germany_population_states_hexagonal.svg|thumb|Population cartogram of the states of Germany. Each hexagon represents 250&thinsp;000 people. The cartogram is topologically correct in that any states that touch on the cartogram also touch in reality.]]
In this approach (also called ''block'' or ''regular cartograms''), each shape is not just scaled or warped, but is reconstructed from a discrete [[tessellation]] of space, usually into squares or hexagons. Each cell of the tessellation represents a constant value of the variable (e.g., 5000 residents), so the number of whole cells to be occupied can be calculated (although rounding error often means that the final area is not exactly proportional to the variable). Then a shape is assembled from those cells, usually with some attempt to retain the original shape, including salient features such as panhandles that aid recognition (for example, [[Long Island]] and [[Cape Cod]] are often exaggerated). Thus, these cartograms are usually homomorphic and at least partially contiguous.

This method works best with variables that are already measured as a relatively low-valued integer, enabling a one-to-one match with the cells. This has made them very popular for visualizing the [[United States Electoral College]] that determines the election of the [[President of the United States|president]], appearing on television coverage and numerous vote-tracking websites.<ref>{{cite news |last1=Bliss |first1=Laura |last2=Patino |first2=Marie |title=How to Spot Misleading Election Maps |url=https://www.bloomberg.com/news/articles/2020-11-03/a-complete-guide-to-misleading-election-maps |newspaper=Bloomberg |date=3 November 2020 |access-date=15 November 2020}}</ref> Several examples of block cartograms were published during the 2016 U.S. presidential election season by ''The Washington Post'',<ref>{{cite news|title=Poll: Redrawing the Electoral Map|url=https://projects.fivethirtyeight.com/2016-election-forecast/?ex_cid=rrpromo#plus&electoral-map|archive-url=https://web.archive.org/web/20160710121436/http://projects.fivethirtyeight.com/2016-election-forecast/?ex_cid=rrpromo#plus&electoral-map|url-status=dead|archive-date=July 10, 2016|newspaper=Washington Post|access-date=4 February 2018}}</ref> the ''FiveThirtyEight'' blog,<ref>{{cite web|title=2016 Election Forecast|url=https://projects.fivethirtyeight.com/2016-election-forecast/?ex_cid=rrpromo#plus&electoral-map|archive-url=https://web.archive.org/web/20160710121436/http://projects.fivethirtyeight.com/2016-election-forecast/?ex_cid=rrpromo#plus&electoral-map|url-status=dead|archive-date=July 10, 2016|website=FiveThirtyEight blog| date=29 June 2016 |access-date=4 February 2018}}</ref> and the ''Wall Street Journal'',<ref>{{cite web|title=Draw the 2016 Electoral College Map|url=http://graphics.wsj.com/elections/2016/2016-electoral-college-map-predictions/|website=Wall Street Journal|access-date=4 February 2018}}</ref> among others.  This is a cartogram for the 2024 and 2028 elections, based on the 2020 Census apportionment:

[[File:Cartogram 2008 red blue.png|thumb|upright=1.6|Mosaic cartogram of United States Electoral College results (scaled by 2008 electors) of four past Presidential elections (1996, 2000, 2004, 2008) {{legend|#ff0001|States carried by the Republican in all four elections}} {{legend|#FF5E5E|States carried by the Republican in three of the four elections}} {{legend|#cccccc|States carried by each party twice in the four elections}}
{{legend|#6D5EFF|States carried by the Democrat in three of the four elections}}
{{legend|#2300ff|States carried by the Democrat in all four elections}}|center]]

The major disadvantage of this type of cartogram has traditionally been that they had to be constructed manually, but recently algorithms have been developed to automatically generate both square and hexagonal mosaic cartograms.<ref name="cano2015">{{cite journal |last1=Cano |first1=R.G. |last2=Buchin |first2=K. |last3=Castermans |first3=T. |last4=Pieterse |first4=A. |last5=Sonke |first5=W. |last6=Speckman |first6=B. |title=Mosaic Drawings and Cartograms |journal=Computer Graphics Forum |date=2015 |volume=34 |issue=3 |pages=361–370 |doi=10.1111/cgf.12648|s2cid=41253089 |url=https://pure.tue.nl/ws/files/90083986/MosaicMapsRevised.pdf }} Proceedings of 2015 Eurographics Conference on Visualization (EuroVis)</ref><ref name="tilegrams">{{cite web |last1=Florin |first1=Adam |last2=Hamel |first2=Jessica |title=Tilegrams |url=https://pitchinteractiveinc.github.io/tilegrams/ |publisher=Pitch Interactive |access-date=15 November 2020}}</ref>