Package 'basemaps'

Get a spatial basemap

Description

These functions (down)load and cache a basemap of a defined extent ext, map_service and map_type and return it as an object of the defined class. Alternatively to defining the following arguments, set_defaults can be used to define basemap preferences once for the running session.

Usage

basemap(
  ext = NULL,
  map_service = NULL,
  map_type = NULL,
  map_res = NULL,
  map_token = NULL,
  map_dir = NULL,
  class = "plot",
  force = FALSE,
  ...,
  verbose = TRUE
)

basemap_plot(
  ext = NULL,
  map_service = NULL,
  map_type = NULL,
  map_res = NULL,
  map_token = NULL,
  map_dir = NULL,
  force = NULL,
  ...,
  verbose = TRUE
)

basemap_magick(
  ext = NULL,
  map_service = NULL,
  map_type = NULL,
  map_res = NULL,
  map_token = NULL,
  map_dir = NULL,
  force = NULL,
  ...,
  verbose = TRUE
)

basemap_png(
  ext = NULL,
  map_service = NULL,
  map_type = NULL,
  map_res = NULL,
  map_token = NULL,
  map_dir = NULL,
  force = NULL,
  ...,
  verbose = TRUE
)

basemap_geotif(
  ext = NULL,
  map_service = NULL,
  map_type = NULL,
  map_res = NULL,
  map_token = NULL,
  map_dir = NULL,
  force = NULL,
  ...,
  verbose = TRUE
)

basemap_terra(
  ext = NULL,
  map_service = NULL,
  map_type = NULL,
  map_res = NULL,
  map_token = NULL,
  map_dir = NULL,
  force = NULL,
  ...,
  verbose = TRUE
)

basemap_raster(
  ext = NULL,
  map_service = NULL,
  map_type = NULL,
  map_res = NULL,
  map_token = NULL,
  map_dir = NULL,
  force = NULL,
  ...,
  verbose = TRUE
)

basemap_stars(
  ext = NULL,
  map_service = NULL,
  map_type = NULL,
  map_res = NULL,
  map_token = NULL,
  map_dir = NULL,
  force = NULL,
  ...,
  verbose = TRUE
)

basemap_ggplot(
  ext = NULL,
  map_service = NULL,
  map_type = NULL,
  map_res = NULL,
  map_token = NULL,
  map_dir = NULL,
  force = NULL,
  ...,
  verbose = TRUE
)

basemap_gglayer(
  ext = NULL,
  map_service = NULL,
  map_type = NULL,
  map_res = NULL,
  map_token = NULL,
  map_dir = NULL,
  force = NULL,
  ...,
  verbose = TRUE
)

basemap_mapview(
  ext = NULL,
  map_service = NULL,
  map_type = NULL,
  map_res = NULL,
  map_token = NULL,
  map_dir = NULL,
  force = NULL,
  ...,
  verbose = TRUE
)

Arguments

ext	extent to be covered by the basemap as any spatial class supported by st_bbox.
map_service	character, a map service, either "osm", "carto" or "mapbox". Default is "osm".
map_type	character, a map type, e.g. "streets". For a full list of available map types, see get_maptypes.
map_res	numeric, resolution of base map in range from 0 to 1.
map_token	character, authentication token for services that require registration, which are "osm_stamen", "osm_stadia", "osm_thunderforest", "maptiler" and "mapbox". Register at https://stadiamaps.com/ (for stamen and stadia), https://www.thunderforest.com/, https://www.maptiler.com/ and/or https://www.mapbox.com/ to get tokens. Ignored for all other map services.
map_dir	character, cache directory where downloaded basemap tiles will be stored. By default, a temporary directory is used, which is destroyed when the session is terminated.
class	character, output class, either either plot (default), magick, png, geotif or if suggested packages are installed, terra, raster, stars, ggplot, gglayer or mapview.
force	logical, whether to force download over cached files or not. Default is FALSE.
...	additional arguments, including browse, logical, for class = "png" and interactive sessions only. Whether to open the png file in the system's default PNG viewer or not. Default is TRUE. col, character vector of colours for transforming single-layer basemaps into RGB, if class = "png" or class = "magick". Default is topo.colors(25). dpi, numeric vector of length 1 or 2 specifying the resolution of the image in DPI (dots per inch) for x and y (in that order) - it is recycled to length 2. etc. (see ?gg_raster for valid arguments when using class = "gglayer" or class = "ggplot", including maxpixels to control resolution of ggplot outputs
verbose	logical, if TRUE, messages and progress information are displayed on the console (default).

Value

A basemap of the defined class in Web/Pseudo Mercator Projection (EPSG: 3857)

Note

See get_maptypes for available map services and their sources.

The use of the map services "osm_thunderforest" and "mapbox" require registration to obtain an API token/key which can be supplied to map_token. Register at https://www.thunderforest.com/ and/or https://www.mapbox.com/ to get a token.

Examples

library(basemaps)

# example extent
data(ext)

# view all available maps
get_maptypes()

# set defaults for the basemap
set_defaults(map_service = "osm", map_type = "terrain_bg")
# for "osm_stamen", "osm_stadia", osm "thunderforest", "maptiler" and "mapbox" maps, 
# you need a API token. Register for free at stadiamaps.com, thunderforest.com, 
# maptiler.com and mapbox.com to get tokens.

## Not run: 
# load and plot basemap (default)
map <- basemap(ext)

# or explicitely as different classes such as:
basemap_magick(ext)
basemap_raster(ext)
basemap_stars(ext)

# or as files:
basemap_geotif(ext)
basemap_png(ext)

# or as plots:
basemap_plot(ext)
basemap_mapview(ext)

# including ggplot2:
basemap_ggplot(ext)

# or as ggplot2 layer:
library(ggplot2)
ggplot() +
basemap_gglayer(ext) +
  scale_fill_identity() +
  coord_sf()

# or, when combined with an sf vector object,
# make sure to use Web/Pseudo Mercator (EPSG 3857), as this is
# the CRS in which all basemaps are returned (see "Value"):
library(sf)
ext <- st_transform(ext,  crs = st_crs(3857))
ggplot() +
  basemap_gglayer(ext) +
  geom_sf(data = ext, color = "red", fill = "transparent") +
  coord_sf() +
  scale_fill_identity()

## End(Not run)

---

Flush basemaps cache

Description

This function flushes the basemaps cache and thereby removes all previously queried and/or composited products from the map directories (temporary or user-defined using the argument map_dir) used during the current session.

Usage

flush_cache()

Value

None.

Examples

library(basemaps)
flush_cache()

---

Example extent

Description

The example datasets contain the sf objects ext and ext_eur that can be used to call basemap and the associated functions.

Usage

data(ext)

data(ext_eur)

Format

sf object

An object of class sf (inherits from data.frame) with 1 rows and 3 columns.

---

Set, get and reset basemaps defaults

Description

These functions set, get or reset the defaults of all map arguments passed to basemap and associated functions.

Usage

set_defaults(
  ext = NULL,
  map_service = NULL,
  map_type = NULL,
  map_res = NULL,
  map_token = NULL,
  map_dir = NULL
)

get_defaults()

reset_defaults()

Arguments

ext	extent to be covered by the basemap as any spatial class supported by st_bbox.
map_service	character, a map service, either "osm", "carto" or "mapbox". Default is "osm".
map_type	character, a map type, e.g. "streets". For a full list of available map types, see get_maptypes.
map_res	numeric, resolution of base map in range from 0 to 1.
map_token	character, authentication token for services that require registration, which are "osm_stamen", "osm_stadia", "osm_thunderforest", "maptiler" and "mapbox". Register at https://stadiamaps.com/ (for stamen and stadia), https://www.thunderforest.com/, https://www.maptiler.com/ and/or https://www.mapbox.com/ to get tokens. Ignored for all other map services.
map_dir	character, cache directory where downloaded basemap tiles will be stored. By default, a temporary directory is used, which is destroyed when the session is terminated.

Value

For get_defaults, a list of defaults, otherwise none.

Examples

library(basemaps)
data(ext)

# set defaults for the basemap
set_defaults(ext = ext, map_service = "osm", map_type = "terrain_bg")

# get defaults
get_defaults()

## Not run: 
# load and return basemap map as raster (default)
map <- basemap()

## End(Not run)

# reset defaults
reset_defaults()

---

Draw extent

Description

This function lets you draw an extent on an interactive map. It is a simple wrapper around mapedit::drawFeatures() written by Tim Appelhans et al.

Usage

draw_ext()

Value

An sf object

Examples

## Not run: 
library(basemaps)

# draw extent interactively
ext <- draw_ext()

# set defaults for the basemap
set_defaults(ext = ext, map_service = "osm", map_type = "terrain_bg")
# for mapbox maps, you need a map_token. Register for free at mapbox.com to get a token

# load and return basemap map as raster (default)
map <- basemap()

## End(Not run)

---

Get supported map types or add new map types

Description

These functions manage map types.

Usage

get_maptypes(map_service = NULL, as_df = FALSE, url_cols = FALSE)

add_maptypes(
  map_service,
  map_type,
  url_endpoint,
  url_xy = "xy",
  url_file_format = ".png",
  url_map_token = as.character(NA),
  auth_error_code = 401,
  url_website = as.character(NA)
)

save_maptypes(file)

load_maptypes(file)

Arguments

map_service	character. for get_maptypes(): optional, either "osm", "osm_stamen", "osm_stadia", "osm_thunderforest", "carto", "mapbox", "esri" or "maptiler". Otherwise, a list of map types for both services is returned. for add_maptypes(): character, name of map service the map type to add belongs to
as_df	logical, whether to return a data.frame instead of a list (defaults to FALSE)
url_cols	logical, whether to include the endpoint URL and auxiliary URL columns (defults to FALSE). Ignored, if as_df = FALSE
map_type	character, name of map type to add
url_endpoint	character, endpoint URL for map service and type to add
url_xy	character, either "xy" or "yx" defining the order the map service to add is expecting tile subscripts in (defaults to "xy")
url_file_format	character, file format the endpoint to add is using (defaults to ".png").
url_map_token	character, optional, request query string used by the endpoint to add for transmitting authentification tokens if required (defaults to NA). Run get_maptypes(as_df = T, url_cols = T)$url_map_token for examples.
auth_error_code	numeric, http error code the endpoint to add uses if authentification failed (defaults to 401)
url_website	character, optional, website URL for the service to add the user is directed to for registering (defaults to NA).
file	character, file name ending on ".csv" that the map types table is saved to or loaded from.

Details

get_maptypes() returns every supported map type that can be used as input to the map_type argument of set_defaults, basemap or associated functions.

add_maptypes() adds custom user-defined map types.

save_maptypes() saves the current map types table (as printed by get_maptypes(as_df = T, url_cols = T)) to a file.

load_maptypes() loads a map types table from file.

Value

A character vector of supported map types

Source

"osm": Open Street Map contributors (https://www.openstreetmap.org/copyright), Open Topo Map (https://opentopomap.org/)

"osm_stamen": Stamen (https://maps.stamen.com/) via Stadia Maps (https://stadiamaps.com/), Open Street Map contributors (https://www.openstreetmap.org/copyright)

"osm_stadia": Stadia Maps (https://stadiamaps.com/), Open Street Map contributors (https://www.openstreetmap.org/copyright)

"osm_thunderforest": Thunderforest (https://www.thunderforest.com/), Open Street Map contributors (https://www.openstreetmap.org/copyright)

"carto": Carto (https://carto.com/)

"mapbox": Mapbox (https://www.mapbox.com)

"esri": Esri (https://www.esri.com/en-us/home)

"maptiler": Esri (https://www.maptiler.com)

See Also

basemap

Examples

# for all services, as list (default:)
get_maptypes()

# for osm only
get_maptypes("osm")
# or
get_maptypes()$osm

# for mapbox only
get_maptypes("mapbox")
# or
get_maptypes()$mapbox

# same for all other map services

# or as data.frame:
get_maptypes(as_df = TRUE)

# or as data.frame including all url columns (endpoints):
get_maptypes(as_df = TRUE, url_cols = TRUE)

# add a custom map service and type yourself:
add_maptypes(
   map_service = "someservice", map_type = "terrain", 
   url_endpoint = "https://tile.someservice.org")

# control further aspects of a custom map service and type:
add_maptypes(
   map_service = "someservice", map_type = "terrain", 
   url_endpoint = "https://tile.someservice.org", 
   url_xy = "xy", #  order in which this service expects tile x and y id
   url_file_format = ".png", 
   url_map_token = "?authtoken=", # query params for auth token
   auth_error_code = 401, 
   url_website = "https://someservice.org"
)

---

Plot raster objects using ggplot

Description

This function plots objects of class SpatRaster, RasterLayer, RasterBrick or RasterStack as ggplot2. It is used internally by basemap* functions that return ggplot plots.

Usage

gg_raster(r, r_type = "RGB", gglayer = F, ...)

Arguments

r	raster of class SpatRaster, RasterLayer, RasterBrick or RasterStack.
r_type	character, either "gradient" or "discrete".
gglayer	logical, if FALSE (default), a ggplot2 plot is returned, if TRUE, a ggplot2 layer is returned.
...	additional arguments, including maxpixels, numeric, maximum number of pixels to be plotted (default: number of pixels in r). Use a value lower then ncell(r) to lower resolution for faster plotting. alpha, numeric between 0 and 1, alpha value of the plotted data (transparency). maxColorValue, numeric, the value to use as colour maximum. interpolate, logical, whether to smooth the plot (default is TRUE).

Value

A ggplot2 object

Examples

library(basemaps)

# example extent
data(ext)

## Not run: 
# terra raster object
map <- basemap_terra(ext)

# plotting raster as ggplot using the with fill aesthetic
gg_raster(map, r_type = "RGB")

# or as gg layer using the with fill aesthetic
ggplot() + gg_raster(map, r_type = "RGB", gglayer = T) + scale_fill_identity()

## End(Not run)

---