Symbology

mf_map() has three main arguments:

• x an sf object
• var the name(s) of a variable(s) to map
• type the map layer type

The following map types are available:

• base: displays sf objects geometries
  
• prop: displays symbols with areas proportional to a quantitative variable (stocks)
  
• choro: areas are shaded according to the variation of a quantitative variable
  
• typo: displays a typology map of a qualitative variable
  
• symb: displays the different modalities of a qualitative variable as symbols
  
• grad: displays graduated symbols
  
• prop_choro: displays symbols with sizes proportional to values of a first variable and colored to reflect the classification of a second quantitative variable
  
• prop_typo: displays symbols with sizes proportional to values of a first variable and and colored to reflect the modalities of a second qualitative variable
  
• symb_choro: displays the different modalities of a first qualitative variable as symbols colored to reflect the classification of a second quantitative variable

Additionaly, mf_raster() can be used to displays raster objects (single/multi band, continuous, classes, intervals).

Map Layout

These functions are dedicated to the map layout design.

Themes

mf_theme() sets a map theme. A theme is a set of graphical parameters that are applied to maps created with mapsf. These parameters are the figure margins, background and foreground colors and mf_title() options. mapsf offers some builtin themes. It’s possible to modify an existing theme or to start a theme from scratch. Themes are persistent across maps produced by mapsf (e.g. they survive a dev.off() call).

🔗 See the online vignette: How to use themes

Export

mf_svg() and mf_png() export maps in SVG and PNG formats, respectively. The exported map width/height ratio will match the one of a spatial object.
SVG export is the perfect solution for editing maps with desktop vector graphics software, such as Inkscape. SVG is a vector graphics file format.
PNG export should be used for maps that do not require further modification. PNG is a raster graphics file format.

🔗 See the online vignette: How to export maps

Base map

mf_map(x, type = "base") displays sf objects geometries.
mf_get_mtq() is used to import a sample dataset as an sf object. Use sf::st_read() to import your own spatial datasets.

Map layout elements are set with mf_title(), mf_credits(), mf_arrow() and mf_scale()).

library(mapsf)
# import the sample data set
mtq <- mf_get_mtq()
# plot municipalities
mf_map(mtq, type = "base")
# layout elements
credits <- paste0("Sources: IGN, 2018\n", "mapsf ", packageVersion("mapsf"))
mf_title("Martinique")
mf_credits(credits)
mf_arrow()
mf_scale()

Proportional Symbols

mf_map(x, var, type = "prop") displays symbols with areas proportional to a quantitative variable (stocks). The inches argument is used to customize the symbols sizes.

# plot municipalities
mf_map(mtq)
# plot population
mf_map(
  x = mtq,
  var = "POP",
  type = "prop",
  inches = 0.25,
  col = "brown4",
  leg_pos = "topright",
  leg_adj = c(0, -3),
  leg_title = "Total population"
)
# layout elements
mf_title("Population Distribution in Martinique")
mf_credits(credits)
mf_arrow()
mf_scale()

Choropleth Map

In choropleth maps, areas are shaded according to the variation of a quantitative variable. They are used to represent ratios or indices.
mf_map(x, var, type = "choro") displays choropleth maps . Arguments nbreaks, and breaks allow to customize the variable classification. mf_get_breaks() allows to classify data outside of the function itself. Colors palettes, defined with pal, can be created with mf_get_pal() or you can use palette names from hcl.pals().

# population density (inhab./km2) using sf::st_area()
mtq$POPDENS <- 1e6 * mtq$POP / sf::st_area(mtq)
# plot population density
mf_map(
  x = mtq,
  var = "POPDENS",
  type = "choro",
  breaks = "geom",
  nbreaks = 5,
  pal = "Teal",
  border = "white",
  lwd = 0.5,
  leg_pos = "bottomleft",
  leg_adj = c(0, 6),
  leg_title = "Population Density\n(inh. / km2)"
)
# layout elements
mf_title("Population Distribution in Martinique")
mf_credits(credits)
mf_arrow()
mf_scale()

Typology Map

mf_map(x, var, type = "typo") displays a typology map of a qualitative variable. val_order is used to set the modalities order in the legend.

mf_label() displays labels on the map.

# plot administrative status
mf_map(
  x = mtq,
  var = "STATUS",
  type = "typo",
  pal = c("aquamarine4", "yellow3", "wheat"),
  lwd = .5,
  val_order = c(
    "Prefecture",
    "Sub-prefecture",
    "Simple municipality"
  ),
  leg_pos = "topright",
  leg_adj = c(0, 1),
  leg_title = ""
)
# labels for a few  municipalities
mf_label(
  x = mtq[mtq$STATUS != "Simple municipality", ], var = "LIBGEO",
  cex = 0.9, halo = TRUE, r = 0.15
)
# layout elements
mf_title("Administrative Status")
mf_credits(credits)
mf_arrow()
mf_scale()

Proportional Symbols using Choropleth Coloration

mf_map(x, var, type = "prop_choro") creates a map of symbols that are proportional to values of a first variable and colored to reflect the classification of a second variable.

expandBB argument in mf_map() allows to expand the map space. Here, we increase the space available on the right of the map to avoid overlaps between the legends and the map.

# Plot the municipalities and expand the map space on the right
mf_map(x = mtq, expandBB = c(0, 0, 0, .15))
# Plot symbols with choropleth coloration
mf_map(
  x = mtq,
  var = c("POP", "MED"),
  type = "prop_choro",
  border = "grey50",
  lwd = 1,
  leg_pos = c("topright"),
  leg_title = c("Population", "Median Income\n(in euros)"),
  breaks = "equal",
  nbreaks = 4,
  pal = "Greens",
  leg_val_rnd = c(0, -2),
  leg_frame = FALSE
)
# layout elements
mf_title("Population & Wealth in Martinique, 2015")
mf_credits(credits)
mf_arrow()
mf_scale()

Proportional Symbols using Typology Coloration

mf_map(x, var, type = "prop_typo") creates a map of symbols that are proportional to values of a first variable and colored to reflect the modalities of a second qualitative variable.

# plot the municipalities and expand the map space on the right
mf_map(x = mtq, expandBB = c(0, 0, 0, .15))
# plot symbols with choropleth coloration
mf_map(
  x = mtq,
  var = c("POP", "STATUS"),
  type = "prop_typo",
  symbol = "square",
  border = "white",
  lwd = .5,
  leg_pos = "topright",
  leg_title = c("Population", "Administrative\nStatus"),
  val_order = c(
    "Prefecture", "Sub-prefecture",
    "Simple municipality"
  )
)
# layout elements
mf_title("Population Distribution in Martinique")
mf_credits(credits)
mf_arrow()
mf_scale()

Label Map

mf_label() is dedicated to the display of labels on a map. The overlap = FALSE argument displays non overlapping labels.

# plot municipalities
mf_map(mtq, col = "#e4e9de", border = "darkseagreen4")
# plot labels
mf_label(
  x = mtq,
  var = "LIBGEO",
  cex = 0.7,
  font = 4,
  halo = TRUE,
  r = 0.1,
  overlap = FALSE,
  q = 3,
  lines = FALSE
)
# layout elements
mf_title("Municipalities of Martinique")
mf_credits(credits)
mf_arrow(pos = "topright")
mf_scale()

Links Map

mf_get_links() creates a link layer from an sf object and a link data.frame (long format).

mf_map(x, var, type = "grad") displays graduated links.

# import the csv file embedded in mapsf
mob <- read.csv(system.file("csv/mob.csv", package = "mapsf"))
# Select links from Fort-de-France (97209))
mob_97209 <- mob[mob$i == 97209, ]
# create an sf object of links
mob_links <- mf_get_links(x = mtq, df = mob_97209)
# Plot the municipalities
mf_map(mtq)
# plot graduated links
mf_map(
  x = mob_links,
  var = "fij",
  type = "grad",
  breaks = c(100, 500, 1000, 4679.0),
  lwd = c(1, 4, 8),
  leg_pos = "topright",
  leg_title = "Nb. of\nCommuters",
  leg_val_rnd = 0
)
# layout elements
mf_title("Commuting to Fort-de-France")
mf_credits(credits)
mf_arrow()
mf_scale()