get_intersecting_geometries {cancensus}R Documentation

Get identifiers for census regions interesecting a geometry

Description

This function returns a list of regions that intersect a given geometry input. This list of regions can be used directly to query census when one is interested in census data for a particular geographic region that does not coincide with defined census geometries. The returned value can be used as the regions parameter in get_census to get corresponding census geographies and variables that cover the give geometry. Input spatial objects can be any sf or sfc class objects such as POINT, MULTIPOINT or POLYGON.

This function comes with CensusMapper API limits

Usage

get_intersecting_geometries(
  dataset,
  level,
  geometry,
  simplified = FALSE,
  use_cache = TRUE,
  quiet = FALSE,
  api_key = Sys.getenv("CM_API_KEY")
)

Arguments

dataset

A CensusMapper dataset identifier.

level

The census aggregation level to retrieve. One of "Regions", "PR", "CMA", "CD", "CSD", "CT", "DA", "EA" (for 1996 census), or "DB" (for 2001-2016 censuses)..

geometry

A valid sf or sfc class object. As long as the geometry is valid, any projection is accepted. Objects will be reprojected as server-side intersections use lat/lon projection.

simplified

If TRUE will return a region list compatible with get_census, otherwise will return a character vector of matching region ids.

use_cache

If set to TRUE (the default) data will be read from the local cache if available.

quiet

When TRUE, suppress messages and warnings.

api_key

An API key for the CensusMapper API. Defaults to options() and then the CM_API_KEY environment variable.

Source

Census data and boundary geographies are reproduced and distributed on an "as is" basis with the permission of Statistics Canada (Statistics Canada 1996; 2001; 2006; 2011; 2016).

Examples


## Not run: 
# Example using a POINT-class object from a pair of lat/lon coordinates
point_geo <- sf::st_sfc(sf::st_point(c(-123.25149, 49.27026)), crs=4326)
regions <- get_intersecting_geometries(dataset = 'CA16', level = 'CT', geometry = point_geo)
census_data <- get_census(dataset='CA16', regions=regions,
                          vectors=c("v_CA16_408","v_CA16_409","v_CA16_410"),
                          level='CT')

# Example using a POLYGON-class object from a bounding box with four coordinates
poly_geo <- sf::st_as_sfc(sf::st_bbox(c(ymin = 49.25, ymax = 49.30,
                          xmin = -123.25, xmax = -123.30)), crs = 4326)
regions <- get_intersecting_geometries(dataset = 'CA16', level = 'CT', geometry = poly_geo)
census_data <- get_census(dataset='CA16', regions=regions,
                         vectors=c("v_CA16_408","v_CA16_409","v_CA16_410"), level='CT')


## End(Not run)

[Package cancensus version 0.4.3 Index]