{arcgislayers} simplifies accessing and managing data the ArcGIS Ecosystem. With it you can:
SpatRaster from {terra}sf objectsIt is recommend you install and use the metapackage {arcgis}. You can install the development version of arcgis like so:
install.packages(
"arcgis",
repos = c("https://r-arcgis.r-universe.dev", "https://cloud.r-project.org")
) Read data from a Feature Service
library(arcgis) #> Attaching core arcgis packages: #> → arcgisutils v0.3.3 #> → arcgislayers v0.3.1.9000 #> → arcgisgeocode v0.2.2 #> → arcgisplaces v0.1.1
arc_open() takes a URL to create a reference to a remote ArcGIS layer, server, or table. The function can return any of the following classes (corresponding to different ArcGIS service types):
FeatureLayerTableFeatureServerImageServerMapServerGroupLayerFor example, you can create a FeatureLayer object based on a Feature Server URL:
furl <- "https://services.arcgis.com/P3ePLMYs2RVChkJx/ArcGIS/rest/services/USA_Counties_Generalized_Boundaries/FeatureServer/0" county_fl <- arc_open(furl) county_fl #> <FeatureLayer> #> Name: USA Counties - Generalized #> Geometry Type: esriGeometryPolygon #> CRS: 4326 #> Capabilities: Query,Extract
You can then use arc_select() to query the feature layer object and return an sf object.
If no arguments are provided to arc_select() the entire feature layer is returned in memory as an sf object.
arc_select(county_fl) #> Simple feature collection with 3144 features and 12 fields #> Geometry type: POLYGON #> Dimension: XY #> Bounding box: xmin: -178.2176 ymin: 18.92179 xmax: -66.96927 ymax: 71.40624 #> Geodetic CRS: WGS 84 #> First 10 features: #> OBJECTID NAME STATE_NAME STATE_FIPS FIPS SQMI POPULATION #> 1 1 Grand Forks County North Dakota 38 38035 51.3 73170 #> 2 2 Grant County North Dakota 38 38037 1.4 2301 #> 3 3 Griggs County North Dakota 38 38039 3.1 2306 #> 4 4 Hettinger County North Dakota 38 38041 2.1 2489 #> 5 5 Kidder County North Dakota 38 38043 1.6 2394 #> 6 6 LaMoure County North Dakota 38 38045 3.5 4093 #> 7 7 Logan County North Dakota 38 38047 1.8 1876 #> 8 8 McHenry County North Dakota 38 38049 2.8 5345 #> 9 9 McIntosh County North Dakota 38 38051 2.5 2530 #> 10 10 McKenzie County North Dakota 38 38053 5.3 14704 #> POP_SQMI STATE_ABBR COUNTY_FIPS Shape__Area Shape__Length #> 1 50.8 ND 035 0.4503702 2.961625 #> 2 1.4 ND 037 0.5040677 3.413506 #> 3 3.2 ND 039 0.2230339 1.949037 #> 4 2.2 ND 041 0.3427475 2.691898 #> 5 1.7 ND 043 0.4378065 2.719487 #> 6 3.6 ND 045 0.3502662 2.702124 #> 7 1.9 ND 047 0.3090110 2.454735 #> 8 2.8 ND 049 0.5877751 3.261400 #> 9 2.5 ND 051 0.2971127 2.421863 #> 10 5.1 ND 053 0.8862776 4.625264 #> geometry #> 1 POLYGON ((-96.88943 47.6739... #> 2 POLYGON ((-102.0034 46.0528... #> 3 POLYGON ((-97.96167 47.2449... #> 4 POLYGON ((-102.0034 46.2058... #> 5 POLYGON ((-100.0885 46.6357... #> 6 POLYGON ((-99.00921 46.2830... #> 7 POLYGON ((-99.04408 46.2833... #> 8 POLYGON ((-100.9647 47.8540... #> 9 POLYGON ((-99.87578 45.9435... #> 10 POLYGON ((-103.6744 47.3320...Filtering using
where or filter_geom arguments
You can also use the fields argument to select columns or the where argument to subset rows.
For example, using a character vector of column names for fields and a simple SQL where clause for where you can select counties with population greater than 1,000,000:
arc_select(
county_fl,
fields = c("state_abbr", "population"),
where = "population > 1000000"
)
#> Simple feature collection with 49 features and 2 fields
#> Geometry type: POLYGON
#> Dimension: XY
#> Bounding box: xmin: -158.2674 ymin: 21.24986 xmax: -71.02671 ymax: 47.77552
#> Geodetic CRS: WGS 84
#> First 10 features:
#> STATE_ABBR POPULATION geometry
#> 1 OH 1264817 POLYGON ((-81.37707 41.3463...
#> 2 OH 1323807 POLYGON ((-83.24282 39.8044...
#> 3 PA 1250578 POLYGON ((-79.86399 40.2007...
#> 4 PA 1603797 POLYGON ((-75.1429 39.8816,...
#> 5 HI 1016508 POLYGON ((-157.6733 21.2980...
#> 6 IL 5275541 POLYGON ((-88.26711 41.9887...
#> 7 AZ 4420568 POLYGON ((-111.0425 33.4759...
#> 8 AZ 1043433 POLYGON ((-110.4522 31.7360...
#> 9 CA 1682353 POLYGON ((-121.4721 37.4777...
#> 10 CA 1165927 POLYGON ((-122.3076 37.8917...
For FeatureLayer and Table objects, and sometimes ImageServers, the list_fields() function can be helpful to check available attributes and build a where query:
list_fields(county_fl)
#> name type alias sqlType nullable
#> 1 OBJECTID esriFieldTypeOID OBJECTID sqlTypeOther FALSE
#> 2 NAME esriFieldTypeString Name sqlTypeOther TRUE
#> 3 STATE_NAME esriFieldTypeString State Name sqlTypeOther TRUE
#> 4 STATE_FIPS esriFieldTypeString State FIPS sqlTypeOther TRUE
#> 5 FIPS esriFieldTypeString FIPS sqlTypeOther TRUE
#> 6 SQMI esriFieldTypeDouble Area in square miles sqlTypeOther TRUE
#> 7 POPULATION esriFieldTypeInteger 2020 Total Population sqlTypeOther TRUE
#> 8 POP_SQMI esriFieldTypeDouble People per square mile sqlTypeOther TRUE
#> 9 STATE_ABBR esriFieldTypeString State Abbreviation sqlTypeOther TRUE
#> 10 COUNTY_FIPS esriFieldTypeString County FIPS sqlTypeOther TRUE
#> 11 Shape__Area esriFieldTypeDouble Shape__Area sqlTypeDouble TRUE
#> 12 Shape__Length esriFieldTypeDouble Shape__Length sqlTypeDouble TRUE
#> editable domain defaultValue length
#> 1 FALSE NA NA NA
#> 2 TRUE NA NA 50
#> 3 TRUE NA NA 20
#> 4 TRUE NA NA 2
#> 5 TRUE NA NA 5
#> 6 TRUE NA NA NA
#> 7 TRUE NA NA NA
#> 8 TRUE NA NA NA
#> 9 TRUE NA NA 2
#> 10 TRUE NA NA 3
#> 11 FALSE NA NA NA
#> 12 FALSE NA NA NA
#> description
#> 1 <NA>
#> 2 {"value":"The name of the county.","fieldValueType":"nameOrTitle"}
#> 3 {"value":"The name for the state in which the county is located.","fieldValueType":"nameOrTitle"}
#> 4 {"value":"The code (two-digit number) for the state in which the county is located.","fieldValueType":"uniqueIdentifier"}
#> 5 {"value":"The combined state and county codes. County codes begin with 001 for each state; use the combined code (five-digit number) to uniquely identify a county in the country.","fieldValueType":"uniqueIdentifier"}
#> 6 {"value":"The area of the county in square miles using the North America Albers Equal Area Conic projection.","fieldValueType":"measurement"}
#> 7 {"value":"The 2020 population of the county.","fieldValueType":"countOrAmount"}
#> 8 {"value":"The 2020 population of the county per square mile.","fieldValueType":"measurement"}
#> 9 {"value":"The two-letter abbreviation for the state in which the county is located.","fieldValueType":"uniqueIdentifier"}
#> 10 {"value":"The code (three-digit number) for the county.","fieldValueType":"uniqueIdentifier"}
#> 11 <NA>
#> 12 <NA>
You can also provide a bbox, sfc, or sfg object to the filter_geom argument to perform a spatial filter. If the sfc object contains more than one geometry, the object is combined with sf::st_union(). See documentation for more (?arc_select).
nc <- sf::st_read(system.file("shape/nc.shp", package="sf"))
#> Reading layer `nc' from data source
#> `/Users/josiahparry/Library/R/arm64/4.5/library/sf/shape/nc.shp'
#> using driver `ESRI Shapefile'
#> Simple feature collection with 100 features and 14 fields
#> Geometry type: MULTIPOLYGON
#> Dimension: XY
#> Bounding box: xmin: -84.32385 ymin: 33.88199 xmax: -75.45698 ymax: 36.58965
#> Geodetic CRS: NAD27
arc_select(
county_fl,
filter_geom = sf::st_bbox(nc[1,])
)
#> Simple feature collection with 6 features and 12 fields
#> Geometry type: POLYGON
#> Dimension: XY
#> Bounding box: xmin: -82.0477 ymin: 35.98946 xmax: -80.83795 ymax: 36.80746
#> Geodetic CRS: WGS 84
#> OBJECTID NAME STATE_NAME STATE_FIPS FIPS SQMI POPULATION
#> 1 467 Johnson County Tennessee 47 47091 58.8 17948
#> 2 1924 Alleghany County North Carolina 37 37005 47.0 10888
#> 3 1926 Ashe County North Carolina 37 37009 60.3 26577
#> 4 2016 Watauga County North Carolina 37 37189 174.4 54086
#> 5 2018 Wilkes County North Carolina 37 37193 84.9 65969
#> 6 2995 Grayson County Virginia 51 51077 34.1 15333
#> POP_SQMI STATE_ABBR COUNTY_FIPS Shape__Area Shape__Length
#> 1 59.3 TN 091 0.07960385 1.290607
#> 2 46.1 NC 005 0.06140165 1.231232
#> 3 61.9 NC 009 0.11428581 1.442112
#> 4 172.6 NC 189 0.08142272 1.287674
#> 5 87.2 NC 193 0.19911944 1.984232
#> 6 34.4 VA 077 0.11578917 1.945424
#> geometry
#> 1 POLYGON ((-81.74091 36.3919...
#> 2 POLYGON ((-81.2397 36.36549...
#> 3 POLYGON ((-81.47258 36.2344...
#> 4 POLYGON ((-81.80605 36.1046...
#> 5 POLYGON ((-81.02037 36.0350...
#> 6 POLYGON ((-81.34512 36.5729... Creating a SpatRaster from an ArcGIS ImageServer
A SpatRaster object from the {terra} package can be extracted from an ImageServer using arc_raster().
arc_raster() will extract the area defined by xmin, ymin, xmax, and ymax. You can optionally specify the width and height of the resultant image. Use format to define what type of image is returned.
img_url <- "https://landsat2.arcgis.com/arcgis/rest/services/Landsat/MS/ImageServer" landsat <- arc_open(img_url) res <- arc_raster( landsat, xmin = -71, ymin = 43, xmax = -67, ymax = 47.5, bbox_crs = 4326, width = 500, height = 500 ) terra::plotRGB(res, 4, 3, 2, scale = max(landsat[["maxValues"]]))Authorization and publication
Authorization is not required for reading any public data sources.
Workflows that require authorization include:
The same functions for reading public ArcGIS Online and Enterprise services (such as arc_open(),arc_read(),arc_select(),arc_raster(), etc.) can be used to read data from non-public services by using the token argument. For more information on tokens and authorization functions, see the authorization article.
The package includes functions to publish data to an ArcGIS Portal:
add_item(): Creates a new FeatureCollection from a sf or data.frame objectpublish_item(): Publishes an existing FeatureLayerpublish_layer(): is a higher level wrapper around both add_item() and publish_item()There are also functions to add or modify data including add_features(), update_features(), and delete_features(). For a more detailed guide to adding, updating, and deleting features, view the tutorial on the R-ArcGIS Bridge website.
These functions all require authorization since data cannot be published or modified anonymously in ArcGIS Online and ArcGIS Enterprise.
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