openmap {mapmisc} | R Documentation |
Downloads map tiles from Openstreetmap.org and other servers.
openmap(x, zoom, path="http://tile.openstreetmap.org/", maxTiles = 9, crs=projection(x), buffer=0, fact=1, verbose=getOption('mapmiscVerbose'), cachePath=getOption('mapmiscCachePath') ) osmTiles(name, xyz, suffix) openmapAttribution(name, type=c('text','latex','markdown','html', 'auto'), short=FALSE)
x |
An |
zoom |
the zoom level, when missing it will be determined by maxTiles. |
path |
Source of map tiles, see http://diseasemapping.r-forge.r-project.org/mapLayers.html. |
maxTiles |
If zoom is missing, zoom will be chosen such that the number of map tiles is less than or equl to this number. |
crs |
Projection for the output, defaulting to the same projection as
|
buffer |
Extend the extent for which the map is requested, in units
of |
fact |
Passed to |
verbose |
Print information about map images being downloaded, defaults to |
cachePath |
Location to store downloaded map images, defaults to |
name |
name of a tile path, if missing a vector of all available tile paths
is returned. |
type |
format for the attribution |
short |
short or long attribution |
xyz |
format of xyz coordinates in URL's |
suffix |
string to append to URL's, i.e. |
These functions download, display, and manipulate map tiles stored in a standard way either on a web server or a local folder.
Map tiles are a set of PNG images that span the world at a set of zoom levels. Zoom level 1 has four 256x256 pixel tiles in a 2x2 pattern over the whole world. In general, zoom level n has 2^n by 2^n tiles. Zoom levels go up to about 17 or 18 depending on the tile server.
See http://diseasemapping.r-forge.r-project.org/mapLayers.html for a full set of map tiles.
Be sure to attribute any maps you publish, the osmAttribution
function will assist. If type = 'auto'
then markdown format will be used unless a variable mdToTex
is defined and equal to TRUE
.
openmap
returns a Raster
with indexed colours,
or a RasterBrick
brick
, with 'red', 'green' and 'blue' layers.
openmapAttribution
returns a character string.
data("netherlands") plot(nldTiles) openmapAttribution(nldTiles, short=TRUE, type='markdown') openmapAttribution("stamen-toner", type='text') myraster = raster(matrix(0,10,10),xmn=8,xmx=18,ymn=0,ymx=10, crs="+proj=longlat +datum=WGS84 +no_defs +ellps=WGS84 +towgs84=0,0,0") values(myraster) = seq(0,1,len=ncell(myraster)) myPoints = SpatialPoints(myraster, proj4string=CRS(proj4string(myraster)))[ seq(1,ncell(myraster),len=5)] names(osmTiles()) ## Not run: mytiles = openmap(myraster, zoom=6) map.new(myraster) plot(mytiles, add=TRUE) points(myPoints,col='red') mytiles = openmap(myPoints, path='waze', verbose=TRUE) map.new(myPoints) plotRGB(mytiles, add=TRUE) points(myPoints, col='red') openmapAttribution(mytiles) ## End(Not run)