Package index • catchmentACS

Package

What the package computes and how the five steps fit together.

catchmentACS catchmentACS-package: catchmentACS: Isochrone-Based Area-Weighted ACS Aggregation

The five steps

The five steps that make the estimates: the drive-time areas, the ACS estimates, the tracts that overlap each area, the margins of error, and the rates.

cacs_run(): Compute ACS estimates for drive-time areas around sites
cacs_isochrone(): Build drive-time areas around sites with a routing service
cacs_acs_prefetch(): Download ACS estimates for the census tracts of one state
cacs_intersect_weight(): Aggregate ACS tract estimates to drive-time areas by area weighting
cacs_propagate_moe(): Compute margins of error for drive-time area estimates
cacs_derive_rates(): Compute rates and their margins of error for drive-time areas

Result summaries

Reading a result, seeing how it was produced, and turning it into a table.

cacs_describe() print(<cacs_description>): Describe how a result was produced
cacs_summary_as_markdown(): Format a summary table as a Markdown table
summary(<cacs_run_result>): Summarize the result of cacs_run()
print(<cacs_run_result>): Print the result of cacs_run()
print(<cacs_run_summary>): Print the summary of a cacs_run() result
as_tibble(<cacs_run_result>): Convert the result of cacs_run() to a plain tibble
group_by(<cacs_run_result>): Group the result of cacs_run()

Maps of one site

Leaflet maps of one site’s drive-time areas, the tracts they overlap, the weighted estimates, and the rates.

cacs_plot_site_pipeline(): Build all four maps for one site
cacs_plot_site_isochrone(): Map a site and its drive-time areas (map 1 of 4)
cacs_plot_site_intersection(): Map the tracts that overlap a drive-time area (map 2 of 4)
cacs_plot_site_weighted(): Map an ACS variable by tract in a drive-time area (map 3 of 4)
cacs_plot_site_rates(): Map a site with its rates and margins of error (map 4 of 4)
format(<cacs_site_plot_pipeline>): Describe the four maps in one line
print(<cacs_site_plot_pipeline>): Print a summary of the four maps

Cache and configuration

Turning the on-disk cache on or off, and finding where it is and what it holds.

cacs_cache_dir(): Get the path of the cache folder
cacs_set_cache(): Turn the cache on or off
cacs_get_cache_state(): Show the cache settings and how often saved results were used
cacs_clear_cache(): Delete saved results from the cache folder
cacs_cache_status(): Summarize the files in the cache folder

Validation and conditions

Checking ACS data and drive-time areas that come from somewhere else, and collecting the package’s messages, warnings, and errors.

cacs_acs_validate(): Check the form of ACS data for census tracts
cacs_validate_iso(): Check drive-time areas and list the problems found
cacs_validate_osrm_endpoint(): Check whether an OSRM server answers a routing request
cacs_capture_conditions(): Capture the package's messages and warnings in a table
catchmentACS-conditions catchmentACS_condition catchmentACS_message catchmentACS_warning catchmentACS_error: Condition classes for messages, warnings, and errors

Rates, margins of error, and drive-time rings

The ACS codes of the five rates, conversion between a margin of error and a standard error, and cumulative drive-time rings.

cacs_acs_default_rates: Numerator and denominator ACS codes of the five built-in rates
cacs_rings_to_cumulative(): Combine drive-time bands into cumulative drive-time areas
cacs_se_to_moe(): Convert a standard error to a margin of error
cacs_moe_to_se(): Convert a margin of error to a standard error

Bundled data

The data objects installed with the package.

cacs_acs_default_vars: ACS variable codes used by default
cacs_alabama_sites: Ten example sites near Alabama city centers