Read spatial data in a bounding box to a simple feature object from multiple sources

An extended version of sf::read_sf() that support reading spatial data based on a file path, URL, or the data name and associated package. A RDS, RDA, or RData file Optionally provide a bounding box to filter data (data is filtered before download or reading into memory where possible).

Usage

read_sf_ext(...)

read_sf_pkg(
  data,
  bbox = NULL,
  package = NULL,
  pkg = NULL,
  fileext = "gpkg",
  filetype = NULL,
  ...
)

read_sf_path(path, bbox = NULL, ...)

read_sf_zip(
  path,
  bbox = NULL,
  exdir = NULL,
  overwrite = TRUE,
  unzip = "internal",
  ...
)

read_sf_rdata(
  path,
  file = NULL,
  refhook = NULL,
  bbox = NULL,
  .name_repair = "check_unique",
  ...
)

read_sf_query(
  path,
  dsn = NULL,
  bbox = NULL,
  query = NULL,
  table = NULL,
  name = NULL,
  name_col = NULL,
  wkt_filter = NULL,
  zm_drop = FALSE,
  .name_repair = "check_unique",
  ...
)

read_sf_excel(
  path,
  sheet = NULL,
  combine_sheets = FALSE,
  bbox = NULL,
  coords = c("lon", "lat"),
  from_crs = 4326,
  geo = FALSE,
  address = "address",
  .name_repair = "check_unique",
  ...
)

read_sf_csv(
  path,
  url = NULL,
  bbox = NULL,
  coords = c("lon", "lat"),
  from_crs = 4326,
  geo = FALSE,
  address = "address",
  wkt = NULL,
  .name_repair = "check_unique",
  show_col_types = FALSE,
  ...
)

read_sf_url(url, bbox = NULL, coords = c("lon", "lat"), ...)

read_sf_esri(
  url,
  bbox = NULL,
  where = NULL,
  name = NULL,
  name_col = NULL,
  coords = c("lon", "lat"),
  from_crs = 4326,
  .name_repair = "check_unique",
  ...
)

read_sf_felt(
  url = NULL,
  bbox = NULL,
  map_id = NULL,
  .name_repair = "check_unique",
  ...
)

read_sf_gist(url, id = NULL, bbox = NULL, nth = 1, ...)

read_sf_gmap(
  url,
  bbox = NULL,
  layer = NULL,
  combine_layers = FALSE,
  zm_drop = TRUE,
  .name_repair = "check_unique"
)

read_sf_download(
  url,
  filename,
  bbox = NULL,
  path = NULL,
  filetype = "geojson",
  prefix = "date",
  method = "auto",
  unzip = FALSE,
  .name_repair = "check_unique",
  ...
)

read_sf_gsheet(
  url,
  sheet = NULL,
  ss = NULL,
  bbox = NULL,
  ask = FALSE,
  coords = c("lon", "lat"),
  from_crs = 4326,
  geo = FALSE,
  address = "address",
  .name_repair = "check_unique",
  ...
)

Arguments

...

Additional parameters passed to multiple functions; see details.

data

Name of a package dataset; used by read_sf_pkg() only.

bbox

A bounding box object; defaults to NULL. If "bbox" is provided, only returns features intersecting the bounding box.

package, pkg

Package name; used by read_sf_pkg() only. pkg is used if package is NULL.

fileext

File extension. If supplied to list_path_filenames() and pattern is NULL, only return file names matching this extension.

filetype

File type supported by sf::read_sf(); Default: 'gpkg'; used by read_sf_pkg() only and required only if the data is in the package cache directory or extdata system files.

path

A file path.

exdir

The directory to extract files to (the equivalent of unzip -d). It will be created if necessary.

overwrite

If TRUE, overwrite existing files (the equivalent of unzip -o), otherwise ignore such files (the equivalent of unzip -n).

unzip

If TRUE, url must be a zip file that is downloaded to a cache folder, unzipped into a temporary directory (created with tempdir()), and then read to a file using the specified file type.

file

The file path to read from/write to.

refhook

A function to handle reference objects.

.name_repair

Passed to repair parameter of vctrs::vec_as_names()

dsn

data source name (interpretation varies by driver - for some drivers, dsn is a file name, but may also be a folder, or contain the name and access credentials of a database); in case of GeoJSON, dsn may be the character string holding the geojson data. It can also be an open database connection.

query

SQL query to select records; see details

table

table can usually be inferred from basename of the data source. table is used to generate a custom query if both name and name_col are provided. Use sf::st_layers(dsn = dsn)[["name"]] to see a list of available table names.

name, name_col

Name value and name column to use in generated a query for sources read with read_sf_query() or read_sf_esri().

wkt_filter

character; WKT representation of a spatial filter (may be used as bounding box, selecting overlapping geometries); see examples

zm_drop

If TRUE, drop Z and/or M dimensions using sf::st_zm

sheet

Sheet to read. Either a string (the name of a sheet), or an integer (the position of the sheet). Ignored if the sheet is specified via range. If neither argument specifies the sheet, defaults to the first sheet.

coords

Character vector with coordinate values. Coordinates must use the same crs as the from_crs parameter.

from_crs

For df_to_sf(), coordinate reference system used by coordinates or well known text in data frame.

geo

If TRUE, use address_to_sf() to geocode address column; defaults to FALSE.

address

Address column name, Default: 'address'

url

A url for a spatial data file, tabular data with coordinates, or a ArcGIS FeatureServer or MapServer to access with esri2sf::esri2sf()

wkt

Name of column with well-known text for geometry. Used by read_sf_csv().

show_col_types

If FALSE, do not show the guessed column types. If TRUE always show the column types, even if they are supplied. If NULL (the default) only show the column types if they are not explicitly supplied by the col_types argument.

where

string for where condition. Default is NULL (equivalent to 1=1) to return all rows.

map_id

A Felt map URL, map ID string, or a named list with a id and type element. If map_id is a list, it must be equivalent to the output from get_felt_map() where the list includes a "id" string and a "type" string with the value "map".

id

The name of a column in which to store the file path. This is useful when reading multiple input files and there is data in the file paths, such as the data collection date. If NULL (the default) no extra column is created.

nth

For read_sf_gist(), the file to return from the gist, e.g. 1 for first, 2 for second. Defaults to 1.

layer

layer name (varies by driver, may be a file name without extension); in case layer is missing, st_read will read the first layer of dsn, give a warning and (unless quiet = TRUE) print a message when there are multiple layers, or give an error if there are no layers in dsn. If dsn is a database connection, then layer can be a table name or a database identifier (see Id). It is also possible to omit layer and rather use the query argument.

combine_layers, combine_sheets

If FALSE (default), return a list with a sf object for each layer or sheet as a separate item. If TRUE, use purrr::map_dfr() to combine layers or sheets into a single sf object using the layer or sheet name as an additional column.

filename

File name; if filename is NULL and path does not include a file extension, name and file extension are both required.

prefix

File name prefix. "date" adds a date prefix, "time" adds a date/time prefix; defaults to NULL.

method

Method to be used for downloading files. Current download methods are "internal", "libcurl", "wget", "curl" and "wininet" (Windows only), and there is a value "auto": see ‘Details’ and ‘Note’.

The method can also be set through the option "download.file.method": see options().

ss

Something that identifies a Google Sheet:

its file id as a string or drive_id
a URL from which we can recover the id
a one-row dribble, which is how googledrive represents Drive files
an instance of googlesheets4_spreadsheet, which is what gs4_get() returns

Processed through as_sheets_id().

ask

If TRUE, ask for the name of the Google Sheet to read if ss is not provided to read_sf_gsheet.

Details

Reading data from a url:

read_sf_url() supports multiple types of urls:

A MapServer or FeatureServer URL
A URL for a GitHub gist with a single spatial data file (first file used if gist contains multiple)
A URL for a spatial data file, CSV file, Excel file, or RDS file (RDA and RData files supported by read_sf_path())
A Google Sheets URL
A public Google Maps URL

Reading data from a package

read_sf_pkg() looks for three types of package data:

Data loaded with the package
External data in the extdata system files folder.
Cached data in the cache directory returned by rappdirs::user_cache_dir()

Additional ... parameters

read_sf_ext() is a flexible function where ... are passed to one of the other read functions depending on the provided parameters. If you are using more than one parameter, all parameters must be named.

read_sf_pkg() and read_sf_download() both pass additional parameters to read_sf_path() which supports query, name_col, name, and table. name and name_col are ignored if a query parameter is provided. If table is not provided, a expected layer name is created based on the file path.