annotation_map_tile function

Add background OSM tiles

Uses rosm::osm.image() to add background tiles. If you are publishing a map using these tiles, make sure to use the proper attribution (e.g., "Copyright OpenStreetMap contributors" when using an OpenStreetMap-based tile set). data

Format

An object of class GeomMapTile (inherits from Geom, ggproto, gg) of length 5.

annotation_map_tile(
  type = "osm",
  zoom = NULL,
  zoomin = -2,
  forcedownload = FALSE,
  cachedir = NULL,
  progress = c("text", "none"),
  quiet = TRUE,
  interpolate = TRUE,
  data = NULL,
  mapping = NULL,
  alpha = 1
)

GeomMapTile

Arguments

• type: The map type (one of that returned by rosm::osm.types )
• zoom: The zoom level (overrides zoomin)
• zoomin: Delta on default zoom. The default value is designed to download fewer tiles than you probably want. Use -1 or 0 to increase the resolution.
• forcedownload: Re-download cached tiles?
• cachedir: Specify cache directory
• progress: Use progress = "none" to suppress progress and zoom output
• quiet: Use quiet = FALSE to see which URLs are downloaded
• interpolate: Passed to grid::rasterGrob()
• data, mapping: Specify data and mapping to use this geom with facets
• alpha: Use to make this layer semi-transparent

Returns

A ggplot2 layer

Examples

library(ggplot2)
load_longlake_data(which = "longlake_waterdf")

ggplot() +
  annotation_map_tile(zoom = 13, cachedir = system.file("rosm.cache", package = "ggspatial")) +
  geom_sf(data = longlake_waterdf, fill = NA, col = "grey50")