feat: cog_find_peers + cog_peer_compare

cog_find_peers selects peers from canonical_fips_xwalk by same-type,
same-state, and population-range (ratio or absolute) criteria,
ordered by |log(pop_ratio)| ascending.

cog_peer_compare accepts the find_peers result (or a plain character
vector of govids), pulls spending for target + peers via cog_spending,
and appends summary rows (summary_p25/p50/p75) so the whole result
can be faceted by `role` in a single ggplot call. Summary rows honor
per_capita + adjust_to_year by picking the right value column.
target_rank reports the target's rank among target+peers at max(years).

Provenance is rewritten with verb = cog_peer_compare and peer_count.

Also: globalVariables('.data') in zzz.R to silence R CMD check on
tidy-eval pronouns.

Tests: 21 new / 120 total pass. devtools::check() 0E/0W/2N.
This commit is contained in:
2026-04-24 11:17:46 -04:00
parent a6b53de2a7
commit cc4d21ec82
6 changed files with 381 additions and 0 deletions
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# Generated by roxygen2: do not edit by hand
export(cog_explain)
export(cog_find_peers)
export(cog_geographic_rollup)
export(cog_peer_compare)
export(cog_revenue)
export(cog_spending)
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# R/peers.R
#' Find peer governments by similarity criteria
#'
#' Selects peer governments from `canonical_fips_xwalk` by combinations of
#' government type, state, and population range. Peers are ordered by
#' `|log(pop_ratio)|` ascending (closest to the target's population first).
#'
#' @param target_govid Character scalar — `canonical_govid` of the target.
#' @param same_type If `TRUE` (default) restrict peers to the target's
#' `govs_type`.
#' @param same_state If `TRUE` restrict peers to the target's `fips_state`.
#' Default `FALSE`.
#' @param pop_range Length-2 numeric vector giving lower/upper bounds.
#' @param is_ratio If `TRUE` (default) `pop_range` is multiplied by the
#' target's `population_acs` to produce absolute bounds. If `FALSE`,
#' `pop_range` is interpreted as absolute population counts.
#' @param pop_year Reserved for future use (selecting ACS vintage). Currently
#' the corpus has a single snapshot so this argument has no effect.
#' @param max_peers Integer cap on the number of peers returned.
#' @return Tibble with columns `canonical_govid`, `gov_name`, `fips_state`,
#' `population_acs`, `pop_ratio`, `rank`.
#' @export
cog_find_peers <- function(target_govid,
same_type = TRUE,
same_state = FALSE,
pop_range = c(0.7, 1.3),
is_ratio = TRUE,
pop_year = NULL,
max_peers = 10L) {
if (!is.character(target_govid) || length(target_govid) != 1L) {
cli::cli_abort("`target_govid` must be a length-1 character string.")
}
if (!is.numeric(pop_range) || length(pop_range) != 2L ||
pop_range[1] >= pop_range[2]) {
cli::cli_abort("`pop_range` must be a length-2 numeric with lo < hi.")
}
con <- .ensure_session()
target_sql <- sprintf(
"SELECT canonical_govid, gov_name, govs_type, fips_state, population_acs
FROM canonical_fips_xwalk
WHERE canonical_govid = %s",
.sql_lit_chr(target_govid)
)
target <- DBI::dbGetQuery(con, target_sql)
if (nrow(target) == 0L) {
cli::cli_abort(c(
"govid {target_govid} not found in corpus.",
i = "v0.1 covers types 0-3 only (state/county/city/township); see vignette('coverage-scope')."
))
}
if (is.na(target$population_acs) || target$population_acs <= 0) {
cli::cli_abort("Target {target_govid} has missing or non-positive population; cannot build pop_ratio band.")
}
if (isTRUE(is_ratio)) {
lo <- target$population_acs * pop_range[1]
hi <- target$population_acs * pop_range[2]
} else {
lo <- pop_range[1]; hi <- pop_range[2]
}
preds <- c(
sprintf("canonical_govid != %s", .sql_lit_chr(target_govid)),
sprintf("population_acs BETWEEN %.6f AND %.6f", lo, hi)
)
if (isTRUE(same_type)) preds <- c(preds, sprintf("govs_type = %d", target$govs_type))
if (isTRUE(same_state)) preds <- c(preds, sprintf("fips_state = %s", .sql_lit_chr(target$fips_state)))
peers_sql <- sprintf(
"SELECT canonical_govid, gov_name, fips_state, population_acs,
population_acs / %.6f AS pop_ratio
FROM canonical_fips_xwalk
WHERE %s
ORDER BY ABS(LN(CAST(population_acs AS DOUBLE) / %.6f))
LIMIT %d",
target$population_acs,
paste(preds, collapse = " AND "),
target$population_acs,
as.integer(max_peers)
)
peers <- tibble::as_tibble(DBI::dbGetQuery(con, peers_sql))
if (nrow(peers) > 0L) peers$rank <- seq_len(nrow(peers))
else peers$rank <- integer(0)
peers
}
#' Compare a target government against a peer set
#'
#' Pulls spending for the target plus a peer set (either a
#' [cog_find_peers()] result or a character vector of `canonical_govid`) and
#' appends peer-distribution summary rows (`summary_p25`, `summary_p50`,
#' `summary_p75`) so the result can be faceted by `role` in a single ggplot
#' call.
#'
#' @param target_govid Character scalar.
#' @param peers A tibble from [cog_find_peers()] or a character vector of
#' `canonical_govid`s.
#' @param category Character scalar or vector.
#' @param years Integer vector.
#' @param per_capita Default `TRUE` — peer compare usually normalizes by
#' population.
#' @param adjust_to_year Integer base year for CPI-U conversion or `NULL`.
#' @return Tibble matching [cog_spending()]'s columns, plus a `role`
#' column taking values `"target"`, `"peer"`, `"summary_p25"`,
#' `"summary_p50"`, or `"summary_p75"`, and `target_rank` (target's rank
#' among target+peers at `max(years)`, NA for other rows). Provenance
#' attribute reports `verb = "cog_peer_compare"` and `peer_count`.
#' @export
cog_peer_compare <- function(target_govid, peers, category, years,
per_capita = TRUE, adjust_to_year = NULL) {
call <- match.call()
if (!is.character(target_govid) || length(target_govid) != 1L) {
cli::cli_abort("`target_govid` must be a length-1 character string.")
}
peer_govids <- if (is.data.frame(peers)) {
as.character(peers$canonical_govid)
} else {
as.character(peers)
}
peer_govids <- peer_govids[!is.na(peer_govids) & nzchar(peer_govids)]
all_govids <- unique(c(target_govid, peer_govids))
r <- cog_spending(all_govids, years, category, per_capita, adjust_to_year)
r$role <- ifelse(r$canonical_govid == target_govid, "target", "peer")
value_col <- .peer_value_col(per_capita, adjust_to_year)
summary_rows <- .peer_summary_rows(r, value_col)
out <- dplyr::bind_rows(r, summary_rows)
rank_val <- .peer_target_rank(r, target_govid, years, value_col)
out$target_rank <- ifelse(out$role == "target", rank_val, NA_integer_)
prov <- attr(r, "provenance") %||% list()
prov$verb <- "cog_peer_compare"
prov$call <- paste(deparse(call), collapse = " ")
prov$peer_count <- length(peer_govids)
prov$target <- list(
canonical_govid = target_govid,
gov_name = unique(r$gov_name[r$role == "target"])
)
attr(out, "provenance") <- prov
out
}
#' @noRd
.peer_value_col <- function(per_capita, adjust_to_year) {
if (!is.null(adjust_to_year)) {
if (isTRUE(per_capita)) "amt_per_capita_real" else "amt_real"
} else {
if (isTRUE(per_capita)) "amt_per_capita_nominal" else "amt_nominal"
}
}
#' @noRd
.peer_summary_rows <- function(r, value_col) {
peer_rows <- r[r$role == "peer", , drop = FALSE]
if (nrow(peer_rows) == 0L) {
return(r[integer(0), , drop = FALSE])
}
s <- peer_rows |>
dplyr::group_by(.data$year, .data$spend_subtype, .data$category) |>
dplyr::reframe(
q = c("p25", "p50", "p75"),
value = stats::quantile(
.data[[value_col]], c(0.25, 0.50, 0.75), na.rm = TRUE
)
)
s$role <- paste0("summary_", s$q)
s$gov_name <- dplyr::case_when(
s$q == "p25" ~ "Peer P25",
s$q == "p50" ~ "Peer median",
s$q == "p75" ~ "Peer P75",
TRUE ~ NA_character_
)
s$canonical_govid <- NA_character_
out <- s[, c("year", "canonical_govid", "gov_name",
"spend_subtype", "category", "role")]
out[[value_col]] <- s$value
out
}
#' @noRd
.peer_target_rank <- function(r, target_govid, years, value_col) {
if (nrow(r) == 0L) return(NA_integer_)
latest <- max(as.integer(years))
latest_rows <- r[r$year == latest &
r$role %in% c("target", "peer"), , drop = FALSE]
if (nrow(latest_rows) == 0L) return(NA_integer_)
ranked <- dplyr::arrange(latest_rows, dplyr::desc(.data[[value_col]]))
tr <- which(ranked$canonical_govid == target_govid)[1]
if (length(tr) == 0L || is.na(tr)) NA_integer_ else as.integer(tr)
}
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invisible(NULL)
}
# Silence R CMD check "no visible binding" for tidy-eval pronouns used in
# dplyr verbs. `.data` comes from rlang and is guaranteed to resolve at
# evaluation time inside dplyr data-masking contexts.
utils::globalVariables(c(".data"))
.onUnload <- function(libpath) {
cog_close()
}
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% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/peers.R
\name{cog_find_peers}
\alias{cog_find_peers}
\title{Find peer governments by similarity criteria}
\usage{
cog_find_peers(
target_govid,
same_type = TRUE,
same_state = FALSE,
pop_range = c(0.7, 1.3),
is_ratio = TRUE,
pop_year = NULL,
max_peers = 10L
)
}
\arguments{
\item{target_govid}{Character scalar — `canonical_govid` of the target.}
\item{same_type}{If `TRUE` (default) restrict peers to the target's
`govs_type`.}
\item{same_state}{If `TRUE` restrict peers to the target's `fips_state`.
Default `FALSE`.}
\item{pop_range}{Length-2 numeric vector giving lower/upper bounds.}
\item{is_ratio}{If `TRUE` (default) `pop_range` is multiplied by the
target's `population_acs` to produce absolute bounds. If `FALSE`,
`pop_range` is interpreted as absolute population counts.}
\item{pop_year}{Reserved for future use (selecting ACS vintage). Currently
the corpus has a single snapshot so this argument has no effect.}
\item{max_peers}{Integer cap on the number of peers returned.}
}
\value{
Tibble with columns `canonical_govid`, `gov_name`, `fips_state`,
`population_acs`, `pop_ratio`, `rank`.
}
\description{
Selects peer governments from `canonical_fips_xwalk` by combinations of
government type, state, and population range. Peers are ordered by
`|log(pop_ratio)|` ascending (closest to the target's population first).
}
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% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/peers.R
\name{cog_peer_compare}
\alias{cog_peer_compare}
\title{Compare a target government against a peer set}
\usage{
cog_peer_compare(
target_govid,
peers,
category,
years,
per_capita = TRUE,
adjust_to_year = NULL
)
}
\arguments{
\item{target_govid}{Character scalar.}
\item{peers}{A tibble from [cog_find_peers()] or a character vector of
`canonical_govid`s.}
\item{category}{Character scalar or vector.}
\item{years}{Integer vector.}
\item{per_capita}{Default `TRUE` — peer compare usually normalizes by
population.}
\item{adjust_to_year}{Integer base year for CPI-U conversion or `NULL`.}
}
\value{
Tibble matching [cog_spending()]'s columns, plus a `role`
column taking values `"target"`, `"peer"`, `"summary_p25"`,
`"summary_p50"`, or `"summary_p75"`, and `target_rank` (target's rank
among target+peers at `max(years)`, NA for other rows). Provenance
attribute reports `verb = "cog_peer_compare"` and `peer_count`.
}
\description{
Pulls spending for the target plus a peer set (either a
[cog_find_peers()] result or a character vector of `canonical_govid`) and
appends peer-distribution summary rows (`summary_p25`, `summary_p50`,
`summary_p75`) so the result can be faceted by `role` in a single ggplot
call.
}
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test_that("cog_find_peers returns same-type peers in the default pop band", {
skip_if_no_corpus()
peers <- cog_find_peers("101006006") # Broward County
expect_s3_class(peers, "tbl_df")
expected_cols <- c("canonical_govid", "gov_name", "fips_state",
"population_acs", "pop_ratio", "rank")
expect_true(all(expected_cols %in% names(peers)))
expect_true(all(peers$pop_ratio >= 0.7 & peers$pop_ratio <= 1.3))
expect_false("101006006" %in% peers$canonical_govid)
expect_equal(peers$rank, seq_len(nrow(peers)))
})
test_that("cog_find_peers respects same_state restriction", {
skip_if_no_corpus()
peers <- cog_find_peers("101006006", same_state = TRUE,
pop_range = c(0.1, 10))
expect_true(all(peers$fips_state == "12"))
})
test_that("cog_find_peers absolute pop range works", {
skip_if_no_corpus()
peers <- cog_find_peers("101006006",
pop_range = c(1.5e6, 2.5e6),
is_ratio = FALSE, max_peers = 20L)
expect_true(all(peers$population_acs >= 1.5e6 &
peers$population_acs <= 2.5e6))
})
test_that("cog_find_peers errors cleanly on unknown govid", {
skip_if_no_corpus()
expect_error(cog_find_peers("XXXINVALID"), "not found")
})
test_that("cog_peer_compare accepts a cog_find_peers result directly", {
skip_if_no_corpus()
peers <- cog_find_peers("101006006", max_peers = 4L)
r <- cog_peer_compare("101006006", peers, "Police", years = 2020L)
expect_s3_class(r, "tbl_df")
expect_true("role" %in% names(r))
expect_setequal(
unique(r$role),
c("target", "peer", "summary_p25", "summary_p50", "summary_p75")
)
expect_equal(sum(r$role == "target" & r$spend_subtype == "operations"), 1L)
})
test_that("cog_peer_compare accepts a character vector of govids", {
skip_if_no_corpus()
r <- cog_peer_compare(
"101006006",
peers = c("441015015", "441220220"), # Bexar, Tarrant
category = "Police", years = 2020L
)
expect_true("peer" %in% r$role)
expect_equal(sum(r$role == "peer" & r$spend_subtype == "operations"), 2L)
})
test_that("cog_peer_compare summary rows use real per-capita when requested", {
skip_if_no_corpus()
r <- cog_peer_compare(
"101006006",
peers = c("441015015", "441220220", "231082082"),
category = "Police", years = 2019:2020,
per_capita = TRUE, adjust_to_year = 2022L
)
summaries <- dplyr::filter(r, grepl("^summary_", role))
expect_true(all(is.finite(summaries$amt_per_capita_real)))
# summary rows have NA canonical_govid and named gov_name
expect_true(all(is.na(summaries$canonical_govid)))
expect_true(all(grepl("Peer", summaries$gov_name)))
})
test_that("cog_peer_compare provenance reports the outer verb + peer count", {
skip_if_no_corpus()
r <- cog_peer_compare("101006006",
peers = c("441015015", "441220220"),
category = "Police", years = 2020L)
prov <- attr(r, "provenance")
expect_equal(prov$verb, "cog_peer_compare")
expect_equal(prov$peer_count, 2L)
})
test_that("cog_peer_compare handles zero peers gracefully", {
skip_if_no_corpus()
r <- cog_peer_compare("101006006",
peers = character(0),
category = "Police", years = 2020L)
expect_true(all(r$role == "target"))
expect_equal(sum(grepl("^summary_", r$role)), 0L)
})