عنوان مقاله [English]
We are accustomed to looking at maps as political or certain units (for example states, countries, census districts) are plotted according to their relative size. So, for example, in the U.S. map the state of Texas appears larger than Rhode Island, Colorado larger than Massachusetts, and so on. The areas on the map are based on the geographical spaces of political units (it is only in non-equivalent area images where these relations are intensified), but it is quite possible that maps be produced on which the spaces of the political units are plotted according to parameters other than geographic space. For example, map areas that represent states may be plotted in proportion to their population, their income, or the number of their retailers, rather than being
proportionate to their geographical size.
Maps that are presented in this way according to different quantities are referred to as Cartogram or "levels of value" or "spatial shape deformation " maps.