Check NAR geocoding results against the BC Address Geocoder

Re-geocodes each address with the BC service and reports how far its answer sits from the one already obtained, in metres. It is the way to answer a question [geocode()] cannot answer about itself – whether a match is right at all – and where the two differ, **BC's answer is the more reliable**: it is a parcel-level provincial authority, while NAR is a national compilation of what provinces and municipalities supplied.

Usage

bc_validate(g, x = g$input, ...)

Arguments

g

A result from [geocode()], with `lon`/`lat` columns or `sf` geometry.

x

The address strings to send. Defaults to `g$input`.

...

Passed to [bc_geocode()], including `min_score` and `api_key`.

Value

`g` with `bc_match_method`, `bc_score`, `bc_precision` and `bc_dist_m` appended. `bc_dist_m` is `NA` where either side has no point.

What a disagreement does and does not prove

The two sources are **not independent** – BC's geocoder and NAR's BC records plausibly share upstream data – so `bc_dist_m` is not a benchmark of NAR's accuracy. Small distances can be two views of one underlying record agreeing with itself, and the distribution is a lower bound on how far apart genuinely independent sources would sit. Use it to find suspect rows, which it does well, rather than to estimate the error `uncertainty_m` excludes.

Rows outside British Columbia are skipped rather than sent, since the service does not cover them and would answer about a BC place of the same name.

Examples

if (FALSE) { # \dontrun{
g <- geocode(c("525 Superior St, Victoria, BC", "800 Robson St, Vancouver, BC"))
bc_validate(g)
} # }