surveilling-surveillance/analysis/figures.R
2021-05-20 13:22:04 -07:00

252 lines
6.9 KiB
R

estimate_detection_metrics <- function(df, recall = 0.63) {
df %>%
left_join(city_data) %>%
transmute(
city,
type,
period,
road_network_length_km ,
m_per_pano,
pop_pano = 2 * road_network_length_km * 1000 / m_per_pano, # N
n_pano,
n_detection,
# detection rate (unadjusted detections per pano)
p_hat = n_detection / n_pano,
# infinite population sd:
p_hat_sd = sqrt(p_hat * (1 - p_hat) / n_pano),
# for finite population sd:
# p_hat_sd = sqrt((p_hat * (1 - p_hat) / n_pano) * ((pop_pano - n_pano) / (pop_pano - 1))),
# detection rate (detections per km counting both sides of the road per km)
est_detections_per_km = p_hat * (1000 / m_per_pano) * (2 / recall),
se_detections_per_km = p_hat_sd * (1000 / m_per_pano) * (2 / recall),
# detection count
est_detections = est_detections_per_km * road_network_length_km,
se_detections = se_detections_per_km * road_network_length_km
) %>%
ungroup() %>%
select(-p_hat, -p_hat_sd)
}
plot_camera_density <- function(df, legend = TRUE) {
if (legend) {
legend_position = "bottom"
} else {
legend_position = "none"
}
df %>%
ggplot(aes(x = city, y = est_detections_per_km, fill = type)) +
geom_col() +
geom_linerange(aes(
ymin = est_detections_per_km - 1.96*se_detections_per_km,
ymax = est_detections_per_km + 1.96*se_detections_per_km
)) +
scale_x_discrete(name = "") +
scale_y_continuous(
name = "Estimated cameras per km",
position = "right",
expand = expansion(mult = c(0, 0.1))
) +
scale_fill_discrete(name = "") +
coord_flip() +
theme(
panel.border = element_blank(),
axis.line = element_line(size = 1, color = "black"),
axis.title.x = element_text(family = "Helvetica", color = "black"),
axis.text = element_text(family = "Helvetica", color = "black"),
legend.position = legend_position,
panel.grid.major.x = element_blank(),
panel.grid.major.y = element_blank(),
panel.grid.minor = element_blank()
)
}
load_road_network <- function(city_name){
stopifnot(city_name %in% city_data$city)
path <- here::here("data", "road_network", city_name, "edges.shp")
read_sf(path)
}
get_max_points <- function(df){
df %>%
select(geometry) %>%
st_cast("POINT") %>%
st_coordinates() %>%
as_tibble() %>%
summarize(
x_max = max(X),
x_min = min(X),
y_max = max(Y),
y_min = min(Y)
)
}
generate_sampled_point_map <- function(df, city_name){
# load road network
road_network <- load_road_network(city_name)
# get crs
road_network_crs <- st_crs(road_network) %>%
as.integer()
road_network_crs <- road_network_crs[1]
# find bounding coordinates of road network
bbox <- st_bbox(road_network)
# plot points
road_network %>%
ggplot() +
geom_sf(fill = "white", color = "gray", alpha = 0.6) +
geom_sf(
data = df %>%
filter(city == city_name) %>%
st_as_sf(coords = c("lon", "lat"),
# ensure same crs as road network
crs = road_network_crs,
agr = "constant"),
color = "blue", size = 0.2,
shape = 16, alpha = 1
) +
scale_x_continuous(expand = expansion(mult = c(0.02, 0.02))) +
scale_y_continuous(expand = expansion(mult = c(0, 0.02))) +
coord_sf(xlim = c(bbox$xmin, bbox$xmax), ylim = c(bbox$ymin, bbox$ymax)) +
theme(
axis.text = element_blank(),
axis.ticks = element_blank(),
panel.grid = element_blank(),
panel.border = element_blank(),
legend.position = "bottom",
legend.text = element_text(size = 20)
)
}
generate_detected_point_map <- function(df, city_name){
# load road network
road_network <- load_road_network(city_name)
# get crs
road_network_crs <- st_crs(road_network) %>%
as.integer()
road_network_crs <- road_network_crs[1]
# find bounding coordinates of road network
bbox <- st_bbox(road_network)
# plot points
road_network %>%
ggplot() +
geom_sf(fill = "white", color = "gray", alpha = 0.6) +
geom_sf(
data = df %>%
filter(
city == city_name,
camera_count > 0
) %>%
st_as_sf(coords = c("lon", "lat"),
# ensure same crs as road network
crs = road_network_crs,
agr = "constant"),
color = "red", size = 0.5,
shape = 16, alpha = 1
) +
scale_x_continuous(expand = expansion(mult = c(0.02, 0.02))) +
scale_y_continuous(expand = expansion(mult = c(0, 0.02))) +
coord_sf(xlim = c(bbox$xmin, bbox$xmax), ylim = c(bbox$ymin, bbox$ymax)) +
theme(
axis.text = element_blank(),
axis.ticks = element_blank(),
panel.grid = element_blank(),
panel.border = element_blank(),
legend.position = "bottom",
legend.text = element_text(size = 20)
)
}
annotate_points_with_census <- function(df, city_name, census_var){
stopifnot(census_var %in% c("income", "race"))
# define state, county using `city_data`
state <- city_data %>%
filter(city == city_name) %>%
pull(state)
county <- city_data %>%
filter(city == city_name) %>%
pull(county)
# specify variables
summary_vars <- "B03002_001" # total population
if (census_var == "income") {
vars <- c(Income = "B19113_001")
} else if (census_var == "race") {
vars <- c(White = "B03002_003") #non-Hispanic white
}
# get census data
if (city_name == "New York") {
state = "NY"
counties <- c("New York County", "Kings County", "Queens County",
"Bronx County", "Richmond County")
new_york <- purrr::map(
counties,
~ get_acs(
state = state,
county = .x,
geography = "block group",
variables = vars,
summary_var = summary_vars,
geometry = TRUE
)
)
df_census_block_group <- bind_rows(new_york)
} else{
if (city_name == "Washington") {
county <- NULL
}
df_census_block_group <- get_acs(
state = state,
county = county,
geography = "block group",
variables = vars,
summary_var = summary_vars,
geometry = TRUE
)
}
# add GIS features
df <- df %>%
filter(city == city_name) %>%
# ensure same coords as tidycensus
st_as_sf(
coords = c("lon", "lat"),
crs = 4269,
agr = "constant"
)
# annotate points with census data
if (census_var == "income") {
df <- st_join(
df,
df_census_block_group %>%
select(GEOID, NAME, median_household_income = estimate, geometry)
)
} else if (census_var == "race") {
df <- st_join(
df,
df_census_block_group %>%
transmute(
GEOID, NAME,
percentage_minority = (summary_est - estimate) / summary_est, geometry
)
)
}
df
}