Geometry only: sfc

Geometry list-columns (objects of class sfc, obtained by the st_geometry method) only show the geometry:

library(sf)
demo(nc, ask = FALSE, echo = FALSE)
plot(st_geometry(nc))

which can be further annotated with colors, symbols, etc., as the usual base plots, e.g. points are added to a polygon plot by:

plot(st_geometry(nc), col = sf.colors(12, categorical = TRUE), border = 'grey', 
     axes = TRUE)
plot(st_geometry(st_centroid(nc)), pch = 3, col = 'red', add = TRUE)

## Warning: st_centroid assumes attributes are constant over geometries

and legends, titles and so on can be added afterwards. border = NA removes the polygon borders.

As can be seen, the axes plotted are sensitive to the CRS, and in case of longitude/latitude coordinates, degree symbols and orientation are added if axes = TRUE.

Geometry with attributes: sf

The default plot of an sf object is a multi-plot of all attributes, up to a reasonable maximum:

plot(nc)

## Warning: plotting the first 10 out of 14 attributes; use max.plot = 14 to plot
## all

with a warning when not all attributes can be reasonably plotted. One can increase the maximum number of maps to be plotted by

plot(nc, max.plot = 14)

The row/column layout is chosen such that the plotting area is maximally filled. The default value for max.plot can be controlled, e.g. by setting the global option sf_max.plot:

options(sf_max.plot=1)
plot(nc)

grid: st_as_grob

Package sf provides a number of methods for st_as_grob():

methods(st_as_grob)

##  [1] st_as_grob.CIRCULARSTRING*      st_as_grob.COMPOUNDCURVE*      
##  [3] st_as_grob.CURVEPOLYGON*        st_as_grob.GEOMETRYCOLLECTION* 
##  [5] st_as_grob.LINESTRING*          st_as_grob.MULTILINESTRING*    
##  [7] st_as_grob.MULTIPOINT*          st_as_grob.MULTIPOLYGON*       
##  [9] st_as_grob.MULTISURFACE*        st_as_grob.POINT*              
## [11] st_as_grob.POLYGON*             st_as_grob.sfc*                
## [13] st_as_grob.sfc_CIRCULARSTRING*  st_as_grob.sfc_LINESTRING*     
## [15] st_as_grob.sfc_MULTILINESTRING* st_as_grob.sfc_MULTIPOINT*     
## [17] st_as_grob.sfc_MULTIPOLYGON*    st_as_grob.sfc_POINT*          
## [19] st_as_grob.sfc_POLYGON*        
## see '?methods' for accessing help and source code

which convert simple simple feature objects into grob (“graphics objects”) objects; grobs are the graphic primitives of the grid plotting package. These methods can be used by plotting packages that build on grid, such as ggplot2 (which uses them in geom_sf()) and tmap. In addition, st_viewport() can be used to set up a grid viewport from an sf object, with an aspect ratio similar to that of plot.sf().

ggplot2

contains a geom specially for simple feature objects, with support for graticule white lines in the background using sf::st_graticule(). Support is currently good for polygons; for lines or points, your mileage may vary.

library(ggplot2)
ggplot() + geom_sf(data = usa)

Polygons can be colored using aes:

ggplot() + 
  geom_sf(data = nc, aes(fill = BIR74)) + 
  scale_y_continuous(breaks = 34:36)

and sets of maps can be plotted as facet plots after rearranging the sf object, e.g. by

library(dplyr)
library(tidyr)
nc2 <- nc %>% select(SID74, SID79, geom) %>% gather(VAR, SID, -geom)
ggplot() + 
  geom_sf(data = nc2, aes(fill = SID)) + 
  facet_wrap(~VAR, ncol = 1) +
  scale_y_continuous(breaks = 34:36)

mapview

Package mapview creates interactive maps in html pages, using package leaflet as a workhorse. Extensive examples are found here.

An example is obtained by

library(mapview)
mapviewOptions(fgb = FALSE) # needed when creating web pages
mapview(nc["BIR74"], col.regions = sf.colors(10), fgb = FALSE)

gives a map which is interactive: you can zoom and pan, and query features by clicking on them.

tmap

Package tmap is another package for plotting maps, with emphasis on production-ready maps.

library(tmap)
qtm(nc)

tmap also has interactive leaflet maps:

tmap_mode("view")
tm_shape(nc) + tm_fill("BIR74", palette = sf.colors(5))

Replotting the last map in non-interactive mode is as simple as:

ttm()
tmap_last()

A draft version of the book Elegant and informative maps with tmap by Martijn Tennekes and Jakub Nowosad is found at https://r-tmap.github.io/