jared
515ab3b019
Rebase onto the v6 main (bd53230) shifted survey_weight from col 26 to
col 28: v5→v6 inserted cog_legacy_state/cog_legacy_county at positions
10-11 (26→28 cols). Position confirmed against the regenerated v6
fixture and both corpus docs (reader-specification.md §3 'Long parquet
schema (28 columns)' row 28; data_dictionary.md '28-column schema v6'
row 28).
2.9 KiB
uscogdata
Curated R reader for the Civilytics US Census of Governments finance corpus.
Provides unit-level financial profiles, geographic rollups, and peer comparisons with auditable provenance and built-in cross-vintage correctness. Reads the published corpus (Hive-partitioned parquet + manifest.json) directly from Nextcloud via DuckDB httpfs — no local bulk downloads required.
Status
Under active development (Phase 2 of the cog_pipeline project). See
../cog_pipeline/docs/reader-specification.md for the reader contract this
package implements.
Installation
# pak::pkg_install("gitea.civilytics.org/Civilytics/uscogdata")
Configuration
USCOGDATA_URL— corpus root URL (public Nextcloud share, trailing slash)USCOGDATA_CACHE_DIR— optional override for the manifest cache directoryUSCOGDATA_MANIFEST_TTL_SECS— optional manifest re-fetch TTL (default 3600)
Raw-parquet caveat: survey_weight is not an aggregation weight
Users reading the corpus parquet directly (DuckDB, arrow) will see a
survey_weight column (schema v6, col 28). It is legacy Census IndFin
sample-design metadata passed through verbatim — the Census Bureau's own
source documentation says it "is for informational purposes only and should
not be used to derive any other statistics" (_ReadMe_First_IndFin.txt;
likewise UserGuide.xls Data User Note 8: "Do not use the weight field to
derive state or national totals"). The raw encoding is also inconsistent
across vintages (reciprocal scale most years, direct scale in 2003, a 1
placeholder in 1967/70/71/73/2001, all-0 in 2007–2012, NA for all
modern-source rows), so sum(amt * survey_weight/10000)-style expressions
produce silently wrong totals — including exact zeros for 2007–2012. Sum
amt unweighted; no uscogdata function reads this column. Full evidence:
cog_pipeline/.superpowers/sdd/weight-semantics-findings.md.
Developer notes
Testing
The package ships a bundled fixture corpus at inst/extdata/fixture_corpus/ —
a 3.6 MB two-year slice (2019 + 2020) of the full corpus covering all 50
states. tests/testthat/setup.R automatically points USCOGDATA_URL at this
fixture, so the full test suite runs offline with no network dependency:
devtools::test() # uses bundled fixture, no credentials required
Releasing against the live corpus
Before cutting a release, run the test suite against the published corpus to catch any drift between the fixture and the real data:
Sys.setenv(USCOGDATA_URL = "<published-corpus-url-with-trailing-slash>")
devtools::test()
When the live-corpus run is clean, strip the fixture from the built package by
adding this line to .Rbuildignore:
^inst/extdata/fixture_corpus$
The test suite is URL-agnostic — setup.R falls back to USCOGDATA_URL when
the bundled fixture is absent, so no test code changes are needed for the
release run or after stripping the fixture.