osm_tile: Low-level tile math

In rosm: Plot Raster Map Tiles from Open Street Map and Other Sources

Low-level tile math

Description

Open Street Map operates using a system of tiles whose value and bounds are easily calculated from WGS84 longitude/latitude. These functions convert between tile system coordinates and longitude/latitude.

Usage

osm_tile(pt, zoom)

osm_tile_quadkey(tile)

osm_tile_top_left(tile, crs = osm_crs_native())

osm_tile_envelope(tile, crs = osm_crs_native())

Arguments

pt	A vector of points as coerced by [wk::as_xy()]. The CRS for these points is considered.
zoom	A zoom level, generally between 0 and 21, with higher values representing a smaller (i.e., more detailed) tile.
tile	A 'data.frame()' with columns 'x', 'y', and 'zoom'.
crs	A target CRS. Either [wk::wk_crs_longlat()] or [osm_crs_native()].

Value

- 'osm_tile()': A 'data.frame()' with columns 'x', 'y', and 'zoom'. - 'osm_tile_top_left()': A [wk::xy()] of the top-left (northwest) corner of the tile. - 'osm_tile_envelope()': A [wk::rct()] of the tile bounds.

Examples

(tiles <- osm_tile(osm_lnglat(-64, 45), zoom = 0:5))
osm_tile_envelope(tiles)

rosm documentation built on Aug. 27, 2023, 9:06 a.m.