¹Utah State University, Department of Mathematics and Statistics, Logan, Utah, USA. Professor. Email: symanzik@math.usu.edu
²Utah State University, Department of Mathematics and Statistics, Logan, Utah, USA. PhD Student. Email: xiaotian.dai@aggiemail.usu.edu
³U.S. Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Office of Research and Development, Corvallis, Oregon, USA. Geographer. Email: Weber.Marc@epa.gov
⁴Oregon State University, Department of Statistics, Corvallis, Oregon, USA. PhD Student. Email: paytonq@science.oregonstate.edu
⁵U.S. Environmental Protection Agency, National Center for Environmental Assessment, Office of Research and Development, Cincinnati, Ohio, USA. Ecologist. Email: McManus.Michael@epa.gov

Linked micromap (LM) plots have been in use in the United States of America (USA) since their introduction in 1996 as an effective way to display statistical summaries associated with regional spatial units. However, LM plots were always hard to create by non--experts. The introduction of the R package has simplified the construction of LM plots for arbitrary geographic regions by facilitating the use of external Geographic Information System (GIS) features (such as shapefiles) as the basis for the maps. In this article, we will introduce LM plots for countries from South America. However, spatial representations of features are often not immediately suitable for LM plots, even after some automated simplification of the boundaries of the map regions. A common problem is that relatively small geographic regions are often not visible when plotted in LM plots. Thus, it is necessary to enlarge small regions and display them on the outside of the main map. We introduce some algorithmic guidelines on how small regions can be addressed in LM plots for South America. Moreover, we will provide recommendations how to include areas into LM plots that are far away from the main geographic region.

Key words: Geographic Data, LM Plots, Map Visualization, R, Statistical Maps, Visualization Software.

Las gráficas de micromapas enlazados (LM por sus siglas en inglés) han sido usados en Estados Unidos desde su introducción en 1996 como una forma efectiva de presentar resúmenes estadísticos asociados con unidades espaciales regionales. Sin embargo, las gráficas LM son difíciles de crear por no expertos. La introducción al paquete R micromap ha simplificado la contrucción de gráficos LM para regiones geográficas arbitrarias al facilitar el uso de Sistemas de Información Geográficos (GIS por sus siglas en inglés) como la base para los mapas. En este artículo, se presentan gráficos LM para los países de Suramérica. Sin embargo, las representaciones espaciales están a menudo no disponibles para los gráficos LM, incluso después de simplificaciones automatizadas de los límites de las regiones. Un problema comón es que regiones geográficamente pequeñas a menuso no son visibles en los gráficos LM. Entonces, se hace necesario ampliar estas regiones pequeñas y mostrarlas por fuera del mapa principal. Se introducen algunas guías algoritmicas de cómo considerar regiones pequeñas en los gráficos LM de Suramérica. Adicionalmente, se dan recomendaciones de cómo incluir áreas que se encuentran lejanas de la principal región geográfica en los graficos LM.

Palabras clave: datos geográficos, gráficos LM, mapas estadísticos, R, Software de visualización, visualización de mapas.

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