tmap

tmap is an R package for thematic mapping and cartography. It provides a unified, high-level framework for creating publication-quality maps from geographic data, with an emphasis on clearly visualizing spatial patterns. The package supports both static maps suitable for reports and presentations, and interactive maps suitable for web pages and dashboards.

tmap operates in two modes: plot mode for static maps and view mode for interactive maps. The mode is switched with the function tmap_mode('plot') or tmap_mode('view'). In plot mode, maps render to static devices; in view mode, maps are rendered in a web-based viewer and can be embedded in HTML or displayed in the RStudio viewer via Leaflet.

Maps are built using a layered, grammar-like syntax. The data source is declared with tm_shape(data), followed by one or more layer calls such as tm_polygons, tm_lines, tm_points, tm_raster, or tm_text to control geometry rendering. Polygons can be styled with tm_fill and tm_borders; colors are chosen from palettes and classification styles (e.g., quantile, jenks, equal). Layout and legends are controlled with tm_layout and related functions, including tm_legend, tm_scale_bar, and tm_compass.

tmap is designed to work with sf objects and supports data from sp for backward compatibility. It can export maps to image or PDF files, or render interactive maps as HTML or within a browser. The package is widely used in education, research, and government for producing thematic choropleth maps, symbol maps, and other cartographic representations.