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Forward geocoding with data frames

Source: R/oc_forward.R
oc_forward_df.Rd

Forward geocoding from a column or vector of location names to latitude and longitude tuples.

Usage

oc_forward_df(...)

# S3 method for class 'data.frame'
oc_forward_df(
  data,
  placename,
  bind_cols = TRUE,
  output = c("short", "all"),
  bounds = NULL,
  proximity = NULL,
  countrycode = NULL,
  language = NULL,
  limit = 1L,
  min_confidence = NULL,
  no_annotations = TRUE,
  roadinfo = FALSE,
  no_dedupe = FALSE,
  abbrv = FALSE,
  address_only = FALSE,
  ...
)

# S3 method for class 'character'
oc_forward_df(
  placename,
  output = c("short", "all"),
  bounds = NULL,
  proximity = NULL,
  countrycode = NULL,
  language = NULL,
  limit = 1L,
  min_confidence = NULL,
  no_annotations = TRUE,
  roadinfo = FALSE,
  no_dedupe = FALSE,
  abbrv = FALSE,
  address_only = FALSE,
  ...
)

Arguments

...

Ignored.

data

A data frame.

placename

An unquoted variable name of a character column or vector with the location names or addresses to be geocoded.

If the locations are addresses, see OpenCage's instructions on how to format addresses for best forward geocoding results.

bind_cols

When bind_col = TRUE, the default, the results are column bound to data. When FALSE, the results are returned as a new tibble.

output

A character vector of length one indicating whether only latitude, longitude, and formatted address variables ("short", the default), or all variables ("all") variables should be returned.

bounds

A list of length one, or an unquoted variable name of a list column of bounding boxes. Bounding boxes are named numeric vectors, each with 4 coordinates forming the south-west and north-east corners of the bounding box: list(c(xmin, ymin, xmax, ymax)). bounds restricts the possible results to the supplied region. It can be specified with the oc_bbox() helper. For example: bounds = oc_bbox(-0.563160, 51.280430, 0.278970, 51.683979). Default is NULL.

proximity

A list of length one, or an unquoted variable name of a list column of points. Points are named numeric vectors with latitude, longitude coordinate pairs in decimal format. proximity provides OpenCage with a hint to bias results in favour of those closer to the specified location. It can be specified with the oc_points() helper. For example: proximity = oc_points(41.40139, 2.12870). Default is NULL.

countrycode

Character vector, or an unquoted variable name of such a vector, of two-letter codes as defined by the ISO 3166-1 Alpha 2 standard that restricts the results to the given country or countries. E.g. "AR" for Argentina, "FR" for France, "NZ" for the New Zealand. Multiple countrycodes per placename must be wrapped in a list. Default is NULL.

language

Character vector, or an unquoted variable name of such a vector, of IETF BCP 47 language tags (such as "es" for Spanish or "pt-BR" for Brazilian Portuguese). OpenCage will attempt to return results in that language. Alternatively you can specify the "native" tag, in which case OpenCage will attempt to return the response in the "official" language(s). In case the language parameter is set to NULL (which is the default), the tag is not recognized, or OpenCage does not have a record in that language, the results will be returned in English.

limit

Numeric vector of integer values, or an unquoted variable name of such a vector, to determine the maximum number of results returned for each placename. Integer values between 1 and 100 are allowed. Default is 1.

min_confidence

Numeric vector of integer values, or an unquoted variable name of such a vector, between 0 and 10 indicating the precision of the returned result as defined by its geographical extent, (i.e. by the extent of the result's bounding box). See the API documentation for details. Only results with at least the requested confidence will be returned. Default is NULL).

no_annotations

Logical vector, or an unquoted variable name of such a vector, indicating whether additional information about the result location should be returned. TRUE by default, which means that the results will not contain annotations.

roadinfo

Logical vector, or an unquoted variable name of such a vector, indicating whether the geocoder should attempt to match the nearest road (rather than an address) and provide additional road and driving information. Default is FALSE.

no_dedupe

Logical vector, or an unquoted variable name of such a vector. Default is FALSE. When TRUE the results will not be deduplicated.

abbrv

Logical vector, or an unquoted variable name of such a vector. Default is FALSE. When TRUE addresses in the oc_formatted variable of the results are abbreviated (e.g. "Main St." instead of "Main Street").

address_only

Logical vector, or an unquoted variable name of such a vector. Default is FALSE. When TRUE only the address details are returned in the oc_formatted variable of the results, not the name of a point-of-interest should there be one at this address.

Value

A tibble. Column names coming from the OpenCage API are prefixed with "oc_".

See also

oc_forward() for inputs as vectors, or oc_reverse() and oc_reverse_df() for reverse geocoding. For more information about the API and the various parameters, see the OpenCage API documentation.

Examples

if (FALSE) { # oc_key_present() && oc_api_ok()

library(tibble)
df <- tibble(
  id = 1:3,
  locations = c("Nantes", "Hamburg", "Los Angeles")
)

# Return lat, lng, and formatted address
oc_forward_df(df, placename = locations)

# Return more detailed information about the locations
oc_forward_df(df, placename = locations, output = "all")

# Do not column bind results to input data frame
oc_forward_df(df, placename = locations, bind_cols = FALSE)

# Add more results by changing the limit from the default of 1.
oc_forward_df(df, placename = locations, limit = 5)

# Restrict results to a given bounding box
oc_forward_df(df,
  placename = locations,
  bounds = oc_bbox(-5, 45, 15, 55)
)

# oc_forward_df accepts unquoted column names for all
# arguments except bind_cols and output.
# This makes it possible to build up more detailed queries
# through the data frame passed to the data argument.

df2 <- add_column(df,
  bounds = oc_bbox(
    xmin = c(-2, 9, -119),
    ymin = c(47, 53, 34),
    xmax = c(0, 10, -117),
    ymax = c(48, 54, 35)
  ),
  limit = 1:3,
  countrycode = c("ca", "us", "co"),
  language = c("fr", "de", "en")
)

# Use the bounds column to help return accurate results and
# language column to specify preferred language of results
oc_forward_df(df2,
  placename = locations,
  bounds = bounds,
  language = language
)

# Different limit of results for each placename
oc_forward_df(df2,
  placename = locations,
  limit = limit
)

# Specify the desired results by the countrycode column
oc_forward_df(df2,
  placename = locations,
  countrycode = countrycode
)
}