data = ("../data/uscities.csv")
us_cities = read_csv(data)

Question 1:

#1.1

eqdc = '+proj=eqdc +lat_0=40 +lon_0=-96 +lat_1=20 +lat_2=60 +x_0=0 +y_0=0 +datum=NAD83 +units=m +no_defs'

#1.2: US State Boundaries
conus = USAboundaries::us_states(resolution = "low") %>% 
  filter(!state_name %in% c("Puerto Rico", "Alaska", "Hawaii")) %>% 
  st_transform(eqdc)


#1.3:North America Country Boundaries 


nat_earth = rnaturalearthdata::countries110

country_bound = st_as_sf(nat_earth) %>% 
  filter(admin %in% c("United States", "Mexico","Canada")) %>%   st_transform(eqdc)

  
#1.4: City Locations 


locations = us_cities %>% 
  st_as_sf(coords = c("lng", "lat"), crs= 4326)%>%
  filter(!state_name %in% c("Puerto Rico", "Alaska", "Hawaii")) %>% 
  st_transform(eqdc)

Question 2:

# 2.1:Distance to US Borders (km)

cb_u_ml <- conus %>% 
  st_union() %>% 
  st_cast("MULTILINESTRING")


us_borders <- locations %>% 
  mutate(border_dist = st_distance(locations, cb_u_ml), 
         border_dist = units::set_units(border_dist, 'km'),
         border_dist = units::drop_units(border_dist)) 

fur_border = us_borders %>% 
  slice_max(border_dist, n = 5) %>% 
  select(city, state_name, border_dist) %>% 
  st_drop_geometry()


#us_borders_df <- as.data.frame(top_us_borders) %>%  #select(city, state_name, border_dist)


knitr::kable(fur_border, caption = 'Top 5 Cities Furthest to USA Border',
             col.names = c("City", "State", "Distance (km)"),
             format.args = list(big.mark = ",")) %>%
  kableExtra::kable_styling("striped", full_width = TRUE, font_size = NULL)
## Warning in kableExtra::kable_styling(., "striped", full_width = TRUE, font_size
## = NULL): Please specify format in kable. kableExtra can customize either HTML or
## LaTeX outputs. See https://haozhu233.github.io/kableExtra/ for details.
Top 5 Cities Furthest to USA Border
City State Distance (km)
Dresden Kansas 1,012.317
Herndon Kansas 1,007.750
Hill City Kansas 1,005.147
Atwood Kansas 1,004.734
Jennings Kansas 1,003.646 
#2.2:Distance to States (km)

cb_c_ml <- conus %>% 
  st_combine() %>% 
  st_cast("MULTILINESTRING")


us_borders <- locations %>% 
  mutate(border_state = st_distance(locations, cb_c_ml), 
         border_state = units::set_units(border_state, 'km')) %>% 
  select(city, state_name, border_state) %>% 
  st_drop_geometry() %>% 
  slice_max(border_state, n = 5) 


knitr::kable(us_borders, caption = 'The Five Cities Farthest from a State Border',
             col.names = c("City", "State", "Distance (km)"),
             format.args = list(big.mark = ",")) %>%
  kableExtra::kable_styling("striped", full_width = TRUE, font_size = NULL)
The Five Cities Farthest from a State Border
City State Distance (km)
Lampasas Texas 308.9216 [km]
Bertram Texas 302.8190 [km]
Kempner Texas 302.5912 [km]
Harker Heights Texas 298.8125 [km]
Florence Texas 298.6804 [km] 
#2.3: Distance to Mexico (km)

mexico <- country_bound %>% 
  filter(sovereignt == "Mexico")

mx_cities <- locations %>% 
  mutate(mx_border = st_distance(locations, mexico), 
         mx_border = set_units(mx_border, 'km')) %>% 
  select(city, state_name, mx_border) %>% 
  slice_max(mx_border, n = 5) %>% 
  arrange(-mx_border)


mx_df <- as.data.frame(mx_cities) %>% 
  select(city, state_name, mx_border)


knitr::kable(mx_df, caption = "Five Cities Farthest from Mexico's Border",
             col.names = c("City", "State", "Distance (km)"),
             format.args = list(big.mark = ",")) %>%
  kableExtra::kable_styling("striped", full_width = TRUE, font_size = NULL)
Five Cities Farthest from Mexico’s Border
City State Distance (km)
Caribou Maine 3,250.334 [km]
Presque Isle Maine 3,234.570 [km]
Calais Maine 3,134.348 [km]
Eastport Maine 3,125.624 [km]
Old Town Maine 3,048.366 [km] 
#2.4:Distance to Canada (km)

canada <- country_bound %>% 
  filter(sovereignt == "Canada")

can_cities <- locations %>% 
  mutate(can_border = st_distance(locations, canada), 
         can_border = set_units(can_border, 'km'),
         can_border = drop_units(can_border)) %>% 
  select(city, state_name, can_border) %>% 
  slice_max(can_border, n = 5) %>% 
  arrange(-can_border)


can_df <- as.data.frame(can_cities) %>% 
  select(city, state_name, can_border)


knitr::kable(can_df, caption = "Five Cities Farthest from Canada's Border",
             col.names = c("City", "State", "Distance (km)"),
             format.args = list(big.mark = ",")) %>%
  kableExtra::kable_styling("striped", full_width = TRUE, font_size = NULL)
Five Cities Farthest from Canada’s Border
City State Distance (km)
Guadalupe Guerra Texas 2,206.455
Sandoval Texas 2,205.641
Fronton Texas 2,204.784
Fronton Ranchettes Texas 2,202.118
Evergreen Texas 2,202.020

Question 3

#3.1: Data

big_cities = locations %>% 
  slice_max(population, n=10) 


ggplot() +
  geom_sf(data = country_bound, col= "black") +
  geom_sf(data = conus, col= "black") +
  geom_sf(data = big_cities, col= "red", size = 2)+
  ggrepel::geom_label_repel(data = big_cities,
    aes(label = city, geometry = geometry),
    stat = "sf_coordinates", size= 3)+
  labs(title = '10 Most Populated US cities',
       x = '',
       y = '')

#3.2: City Distance from the Border

far_cities = fur_border %>% 
  slice_max(border_dist, n=5)


plot_far_cities <-ggplot() + 
  geom_sf(data = conus) +
  geom_sf(data = us_borders, aes(col = border_dist), size = .1) +
  geom_sf(data = far_cities) +
  scale_color_gradient(low = "gray", high = "red") +
  geom_label_repel(data = far_cities, aes( label = city, geometry = geometry), 
                   stat = 'sf_coordinates') +
  labs(title = 'Cities Farthest from the US Border',
       x = 'Longitude',
       y = 'Latitude') +
  theme_gray()
#3.3: City Distance from Nearest State
near_state <- us_borders %>% 
  slice_max(border_state, n=5)



near_plot = ggplot() + 
  geom_sf(data = conus) +
  geom_sf(data = us_borders, aes(col = border_state), size = .1) +
  geom_sf(data = near_state) +
  scale_color_gradient(low = "gray", high = "red") +
  geom_label_repel(data = near_state, aes( label = city, geometry = geometry), 
                   stat = 'sf_coordinates') +
  labs(title = 'Cities Farthest from the US Border',
       x = '',
       y = '') +
  theme_gray()
#3.4: Equidistance boundary from Mexico and Canada

Question 4

#4.1:Quantifing Border Zone


qbz <- locations %>% 
  mutate(sum_pop = sum(population)) %>% 
  mutate(zones = st_distance(locations, cb_u_ml),
         zones = units::set_units(zones, "km"),
         zones = units::drop_units(zones)) %>% 
  filter(zones <= 160) %>% 
  summarise(bor_pop = sum(population), bor_per = (bor_pop/ sum_pop)*100, n_cities = n()) %>% 
  head(1) %>% 
  st_drop_geometry()

knitr::kable(qbz, 
             caption = 'Quantifing Border Zone', 
             col.names = c('Border Zone Population', 'Percent of Total US population', 'Number of Cities'), 
             format.args = list(big.mark = ",")) %>%
  kableExtra::kable_styling("striped", full_width = TRUE, font_size = NULL)
Quantifing Border Zone
Border Zone Population Percent of Total US population Number of Cities
259,935,815 65.43979 12,283 
#4.2: Mapping Border Zone


border_zone <- locations %>%
  st_as_sf(coords = c('lng', 'lat'), crs = 4326) %>%
  mutate(dist_bor = st_distance(locations, cb_u_ml), 
         dist_bor =  units::set_units(dist_bor, 'km'), 
         dist_bor =  units::drop_units(dist_bor)) %>%
  filter(dist_bor <= 160) %>%
  select(city, state_name, dist_bor, population)

most_pop <- border_zone %>%
  select(state_name, population, city) %>%
  arrange(-population) %>%
  head(10)



ggplot() +
  geom_sf(data = conus) +
  geom_sf(data = locations, col = 'grey', size = .1) +
  geom_sf(data = border_zone, aes(col = dist_bor), size = .5) +
  gghighlight(dist_bor <= 160) +
  scale_color_gradient(low = 'orange', high = 'darkred', name = "Distance (km)") +
  geom_label_repel(data = most_pop, aes(label = city, geometry = geometry), stat = 'sf_coordinates') +
  labs(title = "Cities Within 100 km of the US border",
       x = '',
       y = '') +
  theme_gray()
## Warning: Could not calculate the predicate for layer 1, layer 2; ignored