wmts: OGC Webmap Tile Server (WMTS)

In mdsumner/wmts: Read imagery from WebMap Tile Servers

Description

Get raster from WMTS

Usage

wmts(
  x,
  loc,
  buffer = NULL,
  silent = FALSE,
  ...,
  zoom = NULL,
  max_tiles = 9,
  bands = 1:3,
  sds = 1L
)

Arguments

x	WMTS address, either the raw 'WMTSCapabilities.xml' or an expanded GDAL 'WMTS:<url>[],options]' driver data source
loc	something we can get an extent from
buffer	radius in metres (in the case 'loc' is a single point, and is longlat)
silent	suppress messages (default is FALSE)
...	ignored
zoom	override hueristic for zoom level (take care! no safety checks)
max_tiles	max number of tiles for zoom hueristic (default 25)
bands	bands to get (default is 1,2,3 assuming RGB)
sds	which subdataset to read if there are multiple (defaults to 1)

Details

Beware that if 'zoom' is set the 'max_tiles' argument is ignored. Use the function defaults to discover a reasonable zoom level, then re-run with a higher (more pixels) or lower (fewer pixels) zoom level.

Value

raster brick

Examples

centre <- c(-80.888, 32.332)  ## lonlat
radius <- 4000                ## metres
u <- file.path("https://basemap.nationalmap.gov/arcgis/rest",
               "services/USGSTopo/MapServer/WMTS/1.0.0/WMTSCapabilities.xml")
x <- wmts(u, centre, buffer = radius)
# u1 <- sprintf("WMTS:%s,layer=USGSTopo,tilematrixset=default028mm", u)
# x <- wmts(u1, centre, buffer = radius)
# x <- wmts(u, cbind(0, 0), buffer = 20037508)
raster::plotRGB(x, interpolate = TRUE) ## use interpolate to match to device size
#f <- system.file("gpkg/nc.gpkg", package = "sf", mustWork = TRUE)
#sf <- sf::read_sf(f)
#x <- wmts(u, sf)


#tab <- tibble::as_tibble(raster::as.data.frame(x, xy = TRUE))
#names(tab) <- c("x", "y", "red", "green", "blue")
##tab <- dplyr::filter(tab, !is.na(red))
#
### ... when we have missing values, we should drop them or rgb() will error
#tab$hex <- rgb(tab$red, tab$green, tab$blue, maxColorValue = 255)
#library(ggplot2)
#ggplot(tab, aes(x, y, fill = hex)) +
#   geom_raster(interpolate = TRUE) +
#   coord_equal() +
#   scale_fill_identity()

mdsumner/wmts documentation built on July 24, 2021, 3:06 p.m.