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Get sf lines and polygons for insetting the Canary Islands

Source: R/esp_get_can_box.R
esp_get_can_box.Rd

When plotting Spain, it is usual to represent the Canary Islands as an inset (see moveCAN on esp_get_nuts()). These functions provides complementary lines and polygons to be used when the Canary Islands are displayed as an inset.

  • esp_get_can_box() is used to draw lines around the displaced Canary Islands.

  • esp_get_can_provinces() is used to draw a separator line between the two provinces of the Canary Islands.

See also esp_move_can() to displace stand-alone objects on the Canary Islands.

Usage

esp_get_can_box(style = "right", moveCAN = TRUE, epsg = "4258")

esp_get_can_provinces(moveCAN = TRUE, epsg = "4258")

Source

esp_get_can_provinces extracted from CartoBase ANE, se89_mult_admin_provcan_l.shp file.

Arguments

style

Style of line around Canary Islands. Four options available: "left", "right", "box" or "poly".

moveCAN

A logical TRUE/FALSE or a vector of coordinates c(lat, lon). It places the Canary Islands close to Spain's mainland. Initial position can be adjusted using the vector of coordinates. See Displacing the Canary Islands.

epsg

projection of the map: 4-digit EPSG code. One of:

  • "4258": ETRS89.

  • "4326": WGS84.

  • "3035": ETRS89 / ETRS-LAEA.

  • "3857": Pseudo-Mercator.

Value

A sf POLYGON or LINESTRING depending of style parameter.

esp_get_can_provinces returns a LINESTRING object.

Displacing the Canary Islands

While moveCAN is useful for visualization, it would alter the actual geographic position of the Canary Islands. When using the output for spatial analysis or using tiles (e.g. with esp_getTiles() or addProviderEspTiles()) this option should be set to FALSE in order to get the actual coordinates, instead of the modified ones. See also esp_move_can() for displacing stand-alone sf objects.

See also

Other political: esp_codelist, esp_get_capimun(), esp_get_ccaa(), esp_get_comarca(), esp_get_country(), esp_get_gridmap, esp_get_munic(), esp_get_nuts(), esp_get_prov(), esp_get_simpl_prov()

Other Canary Islands: esp_move_can()

Examples


Provs <- esp_get_prov()
Box <- esp_get_can_box()
Line <- esp_get_can_provinces()

# Plot
library(ggplot2)

ggplot(Provs) +
  geom_sf() +
  geom_sf(data = Box) +
  geom_sf(data = Line) +
  theme_linedraw()

# \donttest{
# Displacing Canary

# By same factor

displace <- c(15, 0)

Provs_D <- esp_get_prov(moveCAN = displace)

Box_D <- esp_get_can_box(style = "left", moveCAN = displace)

Line_D <- esp_get_can_provinces(moveCAN = displace)

ggplot(Provs_D) +
  geom_sf() +
  geom_sf(data = Box_D) +
  geom_sf(data = Line_D) +
  theme_linedraw()



# Example with poly option

# Get countries with giscoR

library(giscoR)

# Low resolution map
res <- "20"

Countries <-
  gisco_get_countries(
    res = res,
    epsg = "4326",
    country = c("France", "Portugal", "Andorra", "Morocco", "Argelia")
  )
CANbox <-
  esp_get_can_box(
    style = "poly",
    epsg = "4326",
    moveCAN = c(12.5, 0)
  )

CCAA <- esp_get_ccaa(
  res = res,
  epsg = "4326",
  moveCAN = c(12.5, 0) # Same displacement factor)
)

# Plot

ggplot(Countries) +
  geom_sf(fill = "#DFDFDF") +
  geom_sf(data = CANbox, fill = "#C7E7FB", linewidth = 1) +
  geom_sf(data = CCAA, fill = "#FDFBEA") +
  coord_sf(
    xlim = c(-10, 4.3),
    ylim = c(34.6, 44)
  ) +
  theme(
    panel.background = element_rect(fill = "#C7E7FB"),
    panel.grid = element_blank()
  )

# }