Tektite maps for southeast Asia & Vietnam

tektite-maps-sea-vietnam.R

library(tidyverse)
library(sf)
library(googlesheets4)

# get our data from google sheets, we need to:
# - 'publish to web'
# - adjust sharing settings to share with anyone
# I've done these, now, so it should just work:
my_key <- "1xUqRGnb9kwBi128cERiHkV5w4uREwl-mqAVf0jmQhhg"

# Authorize user on Google
googlesheets4::gs4_auth()

# download the spreadsheet into R
tektite_locations <- 
  my_key %>% 
  read_sheet(sheet = "Geological tektites")

# clean and tidy the coodinates column
# devtools::install_github("ropenscilabs/parzer")
library(parzer)
tektite_locations_clean <- 
  tektite_locations %>% 
  separate(`Location Coordinates (DDM)`, 
           into = c("lat", "lon"), 
           sep = "E|W") %>% 
  mutate(lon = ifelse(str_detect(lon, "S"), paste0("-", lon), lon)) %>% 
  mutate(lon = str_replace_all(lon, regex("N|S|°|'"), " ")) %>% 
  mutate(lat = str_replace_all(lat, regex("°|'"), " ")) %>% 
  mutate(lon = parse_lon(lon)) %>% 
  mutate(lat = parse_lat(lat))  %>% 
  filter_at(vars(lon, lat), ~!is.na(.))

# plot the locations
library(rnaturalearth)
library(rnaturalearthdata)
library(ggspatial)
library(ggrepel)
library(shadowtext)
library(rgeos)

# get a base map
world <- ne_countries(scale = "medium", returnclass = "sf")
vietnam <- ne_countries(scale = "medium", 
                        country = 'vietnam',
                        returnclass = "sf")

# convert to sf object so it has geometry
tektite_locations_clean_sf <- 
  st_as_sf(tektite_locations_clean,
           coords = c("lon", "lat"),
           crs = st_crs(world))

# prepare label text
label_data <- 
  cbind(tektite_locations_clean_sf, 
        st_coordinates(tektite_locations_clean_sf$geometry))

# draw the map
tektite_locations_map <- 
ggplot() +
  geom_sf(data = world,
          fill= "#faebd7") +
  geom_sf(data = tektite_locations_clean_sf,
          colour = "red",
          size = 1) +
  coord_sf(xlim = c(160, 85), 
           ylim = c(-50, 35), 
           expand = FALSE) + 
  geom_label_repel(data = label_data,
                   aes(x = X, 
                       y = Y,
                       label=Map.Label),
                   label.size = NA, 
                   size = 3,
                   alpha = 0.8, 
                   segment.alpha = 0.4,
                   label.padding=0.2, 
                   na.rm=TRUE,
                   force = 40,
                   seed = 1234, 
                   max.overlaps = 100) +
  annotation_scale(location = "bl", 
                   width_hint = 0.5) +
  annotation_north_arrow(location = "bl", 
                         which_north = "true", 
                         pad_x = unit(0.25, "in"), 
                         pad_y = unit(0.25, "in"),
                         style = north_arrow_fancy_orienteering) +
  xlab("Longitude") + 
  ylab("Latitude") + 
  ggtitle("") + 
  theme(panel.background = element_rect(fill = "aliceblue"),
        axis.text.y = element_text(size = 6),
        axis.text.x = element_text(size = 6))

tektite_locations_map

ggsave("tektite-locations-map.png",
       height = 8,
       width = 7)

# draw the map of vietnam only
tektite_locations_clean_sf$vietnam <- 
tektite_locations_clean_sf %>% 
  st_within(vietnam) %>% 
  lengths > 0

tektite_locations_clean_sf$vietnam <- 
  ifelse(tektite_locations_clean_sf$`Map Label` == "Cong Cai", 
         TRUE, 
         tektite_locations_clean_sf$vietnam)

tektite_locations_clean_sf_vietnam <- 
tektite_locations_clean_sf %>% 
  filter(vietnam)

# prepare label text
label_data_vietnam <- 
  cbind(tektite_locations_clean_sf_vietnam, 
        st_coordinates(tektite_locations_clean_sf_vietnam$geometry))

tektite_locations_map_vietnam <- 
ggplot() +
  geom_sf(data = vietnam,
          fill= "#faebd7") +
  geom_sf(data = tektite_locations_clean_sf_vietnam,
          colour = "red",
          size = 1) +
  geom_label_repel(data = label_data_vietnam,
                   aes(x = X, 
                       y = Y,
                       label=Map.Label),
                   label.size = NA, 
                   alpha = 0.8, 
                   segment.alpha = 0.4,
                   label.padding=0.2, 
                   na.rm=TRUE,
                   force = 40,
                   seed = 1234, 
                   max.overlaps = 100) +
annotation_scale(location = "bl", 
                 width_hint = 0.5) +
  annotation_north_arrow(location = "bl", 
                         which_north = "true", 
                         pad_x = unit(0.25, "in"), 
                         pad_y = unit(0.25, "in"),
                         style = north_arrow_fancy_orienteering) +
  xlab("Longitude") + 
  ylab("Latitude") + 
  ggtitle("") + 
  theme(panel.background = element_rect(fill = "aliceblue"),
        axis.text.y = element_text(size = 6),
        axis.text.x = element_text(size = 6))

tektite_locations_map_vietnam

ggsave("tektite-locations-vietnam-map.png",
       height = 8,
       width = 4)

library(cowplot)
plot_grid(tektite_locations_map,
          tektite_locations_map_vietnam,
          ncol = 2,
          align = "hv",
          axis = "tb",
          rel_widths = c(2, 1)
          ) +
  theme(panel.background = element_rect(fill='white',
                                        colour = "white"),
        plot.background = element_rect(fill='white',
                                       colour = "white"))

ggsave("tektite-locations-panel-map.png",
       height = 6,
       width = 10)