CODEWITHSUNDEEP
rggplot2gisr-sftmap
matt_lnrd
matt_lnrd

Reputation: 339

Map dropping countries when plotting with ggplot

Ok, I'm having a hard time with mapping some data by country. Here's a trimmed-down version of the data set I'm working with, in an object called 'smaller':

COUNTRY       ARRIVALS
Algeria         16          
American Samoa  2           
Angola          9           
Antigua Barbuda 2           
Argentina       18          
Aruba           4           
Australia       82          
Bahamas         12          
Bahrain          7          
Bangladesh      19

And here is the code I've tried thus far that I found online:

library(tidyverse)

world_map <- map_data("world")

allmap <- left_join(smaller, world_map, by = c("COUNTRY" = "region"))

ggplot(allmap, aes(long, lat, group = group))+
  geom_polygon(aes(fill = ARRIVALS), color = "white")+
  scale_fill_viridis_c(option = "C")

But this outputs the following map, which is not right at all. enter image description here

Let me know what I'm doing wrong. I appreciate the help.

Upvotes: 1

Views: 661

Answers (2)

Allan Cameron
Allan Cameron

Reputation: 174468

A left join works, provided you also plot world_map as a separate layer:

library(tidyverse)

world_map <- map_data("world")

smaller <- structure(list(COUNTRY = c("Algeria", "American Samoa", "Angola", 
            "Antigua Barbuda", "Argentina", "Aruba", "Australia", "Bahamas", 
            "Bahrain", "Bangladesh"), ARRIVALS = c(16, 2, 9, 2, 18, 4, 82, 
             12, 7, 19)), class = "data.frame", row.names = c(NA, -10L))

allmap <- left_join(smaller, world_map, by = c("COUNTRY" = "region"))

ggplot(allmap, aes(long, lat, group = group))+
  geom_polygon(data = world_map, fill = "#306020", colour = "#00000010") +
  geom_polygon(aes(fill = ARRIVALS), colour = "white") +
  scale_fill_viridis_c(option = "C") +
  theme_classic() +
  theme(panel.background = element_rect(fill = "#101045")) +
  coord_equal()

enter image description here

Upvotes: 0

g_t_m
g_t_m

Reputation: 714

You should be using full_join(). From the documentation:

The mutating joins add columns from y to x, matching rows based on the keys:

inner_join(): includes all rows in x and y.

left_join(): includes all rows in x.

right_join(): includes all rows in y.

full_join(): includes all rows in x or y.

Like so:

library(tidyverse)

smaller <-
  tibble::tribble(
    ~COUNTRY, ~ARRIVALS,
    "Algeria", 16L,
    "American Samoa",  2L,
    "Angola",  9L,
    "Antigua Barbuda",  2L,
    "Argentina", 18L,
    "Aruba",  4L,
    "Australia", 82L,
    "Bahamas", 12L,
    "Bahrain",  7L,
    "Bangladesh", 19L
  )

world_map <- map_data("world")

allmap <- full_join(smaller, world_map, by = c("COUNTRY" = "region"))

ggplot(allmap, aes(long, lat, group = group))+
  geom_polygon(aes(fill = ARRIVALS), color = "white")+
  scale_fill_viridis_c(option = "C")

Created on 2020-07-02 by the reprex package (v0.3.0)

Upvotes: 1

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