arcpullr has the capability to query not only vector
(Feature) layers, but also raster layers (both Map and Image service
types). The syntax for these is generally the same as for the
get_layer_by_* family of functions. Map and Image layers
require a bounding box as part of the query, so both
get_map_layer and get_image_layer have
required arguments of a URL and an sf object. These
functions pull the raster layers provided by the URL and return the
layer as a RasterLayer object from the raster package.
# WDNR Server
image_server <- "https://dnrmaps.wi.gov/arcgis_image/rest/services/"
# WI Landcover Type URL
landcover_path <- "DW_Land_Cover/EN_Land_Cover2_Lev2/MapServer"
landcover_url <- paste0(image_server, landcover_path)
# WI Leaf-off Aerial Imagery URL
wi_leaf_off_path <- "DW_Image/EN_Image_Basemap_Leaf_Off/ImageServer"
wi_aerial_imagery_url <- paste0(image_server, wi_leaf_off_path)
# the wis_poly polygon is available as an exported object in arcpullrThe get_map_layer function takes a URL and an sf object.
Since the query for this layer type on an ArcGIS REST Service requires a
bounding box any sf object can be used (i.e. POLYGON, POINT, LINE, etc.)
and a bounding box will be created using the extent of the shape.
The example below pulls Wisconsin landcover types and plots them in a map.
wi_landcover <- get_map_layer(landcover_url, wis_poly)
plot_layer(wi_landcover)#> The legacy packages maptools, rgdal, and rgeos, underpinning the sp package,
#> which was just loaded, will retire in October 2023.
#> Please refer to R-spatial evolution reports for details, especially
#> https://r-spatial.org/r/2023/05/15/evolution4.html.
#> It may be desirable to make the sf package available;
#> package maintainers should consider adding sf to Suggests:.
#> The sp package is now running under evolution status 2
#> (status 2 uses the sf package in place of rgdal)