Argentine WFS and WMS geospatial services in R • Argentum

Datos geoespaciales públicos argentinos, directo a R. Argentine public geospatial data, straight into R.

Español

Muchos organismos públicos argentinos —el IGN, catastros provinciales, municipios, universidades— publican sus capas geográficas a través de dos estándares abiertos del OGC: WFS, que devuelve geometrías y atributos, y WMS, que devuelve una imagen ya dibujada por el servidor.

Están ahí, son gratis, y casi nadie los usa. El problema no es el acceso: es que cada servidor implementa el estándar a su manera. Uno habla WFS 2.0.0, otro se quedó en 1.1.0. Uno entiende GeoJSON, otro solo GML. Uno devuelve un error dentro de un HTTP 200. Uno invierte el orden de los ejes.

Argentum absorbe esas diferencias.

Instalación

# install.packages("pak")
pak::pak("thomasartopoulos/argentum")

Los cinco minutos iniciales

library(Argentum)

# 1. ¿Quién publica qué?
orgs <- argentum_organizations()          # catálogo de IDERA
argentum_search_organizations("catastro")

# 2. ¿Qué capas tiene un organismo?
ign <- "https://wms.ign.gob.ar/geoserver/ows"
capas <- argentum_layers(ign)
head(capas[, c("name", "title")])

# 3. Traer una capa como sf
provincias <- argentum_read_wfs(ign, "ign:provincia")
plot(sf::st_geometry(provincias))

Referencia rápida

Todas las funciones empiezan con argentum_: escribí eso en la consola y apretá TAB para verlas todas. Qué hace cada una:

Función	Qué hace	Devuelve
`argentum_organizations()`	El catálogo de organismos con geoservicios, según IDERA	data frame
`argentum_search_organizations("catastro")`	Busca en ese catálogo por expresión regular	data frame
`argentum_layers(org)`	Las capas que publica un organismo o URL	data frame
`argentum_capabilities(org)`	El `GetCapabilities` crudo, con la versión ya negociada	objeto imprimible
`argentum_read_wfs(org, capa)`	Lee una capa vectorial (geometrías + atributos)	`sf`
`argentum_read_wms(org, capa, bbox)`	Pide el mapa ya dibujado por el servidor	`terra::SpatRaster`
`argentum_wms_legend(org, capa)`	La leyenda de esa capa WMS	`terra::SpatRaster`
`argentum_download(org, dir)`	Baja capas a disco y reporta qué falló	data frame (reporte)
`argentum_browse()`	Elegir organismo y capa de forma interactiva	—
`argentum_help()`	Guía por temas en la consola, con código para copiar	—
`argentum_cache_path()` / `argentum_cache_clear()`	Dónde vive el caché / vaciarlo	ruta / —

La misma tabla, agrupada y con ejemplos, está en ?argentum y en la referencia del sitio. Las funciones de la 1.x (argentum_list_organizations(), etc.) siguen andando con un aviso; ver vignette("migrating-to-2-0").

Bajar solo lo que necesitás

Pedir una capa nacional entera para mirar un partido del conurbano es tirar ancho de banda a la basura —tuyo y del organismo. El filtro viaja al servidor:

argentum_read_wfs(
  ign, "ign:provincia",
  bbox   = c(-59, -35, -57, -34),   # solo este recorte
  crs    = 4326,                    # reproyectado
  filter = "nam = 'Buenos Aires'"   # filtro CQL, del lado del servidor
)

Las capas grandes se traen paginadas de forma automática. Si el servidor no sabe devolver GeoJSON, Argentum reintenta en GML sin que tengas que hacer nada.

WMS: mapas rasterizados

Novedad de la 2.0. Devuelve un terra::SpatRaster georreferenciado, listo para combinar con datos vectoriales:

base <- argentum_read_wms(
  ign,
  layer = "ign:provincia",
  bbox  = c(-59, -35, -57, -34),
  width = 1000
)

terra::plotRGB(base)
plot(sf::st_geometry(provincias), add = TRUE, border = "white", lwd = 2)

Bajar a disco

reporte <- argentum_download(ign, dir = "datos/ign", format = "gpkg")
subset(reporte, status == "error")   # qué falló y por qué

Un error en una capa no aborta la corrida: queda registrado en el reporte y sigue con la siguiente.

Configuración

Opción	Default	Para qué
`argentum.timeout`	`30`	Segundos por request
`argentum.max_tries`	`3`	Reintentos con backoff exponencial
`argentum.page_size`	`5000`	Features por página de WFS
`argentum.cache_ttl`	`86400`	Vida del caché, en segundos
`argentum.catalog`	`NULL`	Ruta a tu propio CSV de endpoints
`argentum.quiet`	`FALSE`	Silenciar los mensajes de progreso

Los servidores públicos son lentos y a veces se caen. Argentum cachea el catálogo y los GetCapabilities en disco (argentum_cache_path()), así que volver a correr un script no vuelve a golpear el servidor.

¿Venís de la 1.x?

Todo lo de la 1.x sigue funcionando, con un aviso de deprecación (se van en la 3.0.0):

1.x (deprecada)	Usá ahora
`argentum_list_organizations()`	`argentum_organizations()`
`argentum_list_layers()`	`argentum_layers()`
`argentum_get_capabilities()`	`argentum_capabilities()`
`argentum_import_wfs_layer()`	`argentum_read_wfs()`
`argentum_download_layers()`	`argentum_download()`
`argentum_select_organization()`	`argentum_search_organizations()`
`argentum_interactive_import()`	`argentum_browse(action = "read")`
`argentum_interactive_download()`	`argentum_browse(action = "download")`

Detalles y diferencias de argumentos: vignette("migrating-to-2-0").

English

Argentine public bodies — the national geographic institute, provincial cadastres, municipalities, universities — publish their geographic layers through two open OGC standards: WFS, which returns geometries and attributes, and WMS, which returns an image the server has already drawn.

The data is there and it is free. The obstacle is not access, it is that every server implements the standard slightly differently. One speaks WFS 2.0.0, another stopped at 1.1.0. One understands GeoJSON, another only GML. One returns an error inside an HTTP 200. One flips the axis order.

Argentum absorbs those differences.

Installation

# install.packages("pak")
pak::pak("thomasartopoulos/argentum")

First five minutes

library(Argentum)

# 1. Who publishes what?
orgs <- argentum_organizations()          # IDERA's catalogue
argentum_search_organizations("cadastre")

# 2. Which layers does an organization offer?
ign <- "https://wms.ign.gob.ar/geoserver/ows"
layers <- argentum_layers(ign)
head(layers[, c("name", "title")])

# 3. Pull a layer in as sf
provinces <- argentum_read_wfs(ign, "ign:provincia")
plot(sf::st_geometry(provinces))

Quick reference

Every function starts with argentum_: type that at the console and press TAB to see them all. What each one does:

Function	What it does	Returns
`argentum_organizations()`	The catalogue of publishing organizations, per IDERA	data frame
`argentum_search_organizations("cadastre")`	Search that catalogue by regular expression	data frame
`argentum_layers(org)`	The layers an organization or URL publishes	data frame
`argentum_capabilities(org)`	The raw `GetCapabilities`, version already negotiated	printable object
`argentum_read_wfs(org, layer)`	Read a vector layer (geometries + attributes)	`sf`
`argentum_read_wms(org, layer, bbox)`	Fetch the map as the server draws it	`terra::SpatRaster`
`argentum_wms_legend(org, layer)`	The legend for that WMS layer	`terra::SpatRaster`
`argentum_download(org, dir)`	Write layers to disk, reporting what failed	data frame (report)
`argentum_browse()`	Pick an organization and layer interactively	—
`argentum_help()`	Topic-by-topic console guide, with copy-pasteable code	—
`argentum_cache_path()` / `argentum_cache_clear()`	Where the cache lives / empty it	path / —

The same table, grouped and with examples, lives in ?argentum and on the reference site. The 1.x functions (argentum_list_organizations(), etc.) still work with a warning; see vignette("migrating-to-2-0").

Fetch only what you need

Downloading a national layer to look at one district wastes bandwidth — yours and the publisher’s. Filters are pushed to the server:

argentum_read_wfs(
  ign, "ign:provincia",
  bbox   = c(-59, -35, -57, -34),   # this window only
  crs    = 4326,                    # reprojected
  filter = "nam = 'Buenos Aires'"   # CQL filter, evaluated server-side
)

Large layers are paginated automatically. If the endpoint cannot produce GeoJSON, the request silently retries as GML.

WMS: rendered maps

New in 2.0. Returns a georeferenced terra::SpatRaster that composes directly with vector data:

basemap <- argentum_read_wms(
  ign,
  layer = "ign:provincia",
  bbox  = c(-59, -35, -57, -34),
  width = 1000
)

terra::plotRGB(basemap)
plot(sf::st_geometry(provinces), add = TRUE, border = "white", lwd = 2)

Writing to disk

report <- argentum_download(ign, dir = "data/ign", format = "gpkg")
subset(report, status == "error")   # what failed, and why

One broken layer does not abort the run; it is recorded and the loop continues.

Options

Option	Default	Purpose
`argentum.timeout`	`30`	Seconds per request
`argentum.max_tries`	`3`	Retries, with exponential backoff
`argentum.page_size`	`5000`	Features per WFS page
`argentum.cache_ttl`	`86400`	Cache lifetime, in seconds
`argentum.catalog`	`NULL`	Path to your own endpoint CSV
`argentum.quiet`	`FALSE`	Silence progress messages

Public servers are slow and occasionally down. The catalogue and every GetCapabilities document are cached on disk under argentum_cache_path(), so re-running a script does not hit the server again.

Coming from 1.x?

Every 1.x function still works, with a deprecation warning (removed in 3.0.0):

1.x (deprecated)	Use instead
`argentum_list_organizations()`	`argentum_organizations()`
`argentum_list_layers()`	`argentum_layers()`
`argentum_get_capabilities()`	`argentum_capabilities()`
`argentum_import_wfs_layer()`	`argentum_read_wfs()`
`argentum_download_layers()`	`argentum_download()`
`argentum_select_organization()`	`argentum_search_organizations()`
`argentum_interactive_import()`	`argentum_browse(action = "read")`
`argentum_interactive_download()`	`argentum_browse(action = "download")`

Argument-level differences: vignette("migrating-to-2-0").

Citation / Cómo citar

citation("Argentum")

License

MIT © Thomas Artopoulos. The data retrieved through this package remains subject to the terms of each publishing organization.