Overview

The Isole Åland belonged to the provinces that the Swedish Empire had to cede to the Russian Empire with the Treaty of Fredrikshamn in September 1809, and became part of the semi-autonomous Grand Duchy of Finland

This is the reference for identifying ISO3 codes: ISO3 reference

We need wrld_simpl for the shapefiles:

library(tidyverse)
library(maptools)
data(wrld_simpl)
#unique(wrld_simpl$ISO3)
plot(wrld_simpl %>% subset(., ISO3 %in% c("ALA")))

ala<- wrld_simpl$ISO3[wrld_simpl$ISO3=="ALA"]
shape_df <- fortify(wrld_simpl, region = 'ISO3')

shape_df%>%
  filter(id=="ALA")%>%count(group)

shape_short<- shape_df%>%
  filter(id=="ALA")%>%
  mutate(group_names=case_when(group=="ALA.1"~"Åland",
                               group=="ALA.2"~"Lemland",
                               group=="ALA.3"~"Eckero",
                               group=="ALA.4"~"Lumparland",
                               group=="ALA.5"~"Vardo"))

made with ggplot2:

library(extrafont)
loadfonts()
fonts()
family<- "Arial Rounded MT Bold"



ala_pol_map <- ggplot() +
  geom_polygon(data =shape_short , aes(x = long, y = lat, group = group_names, 
               fill = group_names), color = 'black') +
  geom_point(aes(x=19.944444, y=60.098611),color="darkred",size=4)+
  
  
  ggtitle(label = " ")+
  scale_fill_viridis_d()+
  guides(fill=guide_legend(title.position ="top"))+
  labs(fill="",
       captions="\n#30DayMapChallenge Day3 Polygons\n\nDatasource: wrld_simpl {maptools} - Infographics: Federica Gazzelloni\n")+
  ggthemes::theme_map()+
  theme(text = element_text(family=family),
        legend.text = element_text(family=family,size=14),
        legend.direction = "vertical",
        legend.background = element_blank(),
        legend.key = element_rect(size=3),
        plot.caption = element_text(hjust=0.5,vjust=2,size=11,colour = "black",family=family),
        plot.title = element_text(size=34,vjust=1),
        plot.title.position = "panel",
        plot.background = element_rect(fill=NA, color=NA, size=20)
        )


# final touches
library(cowplot)
library(magick)

image<- magick::image_read(here::here("day3_polygons/capitol.png"))

final <- cowplot::ggdraw(ala_pol_map)+
  draw_image(image,x = 0.8, y = 0.38,width = 0.1)+
  draw_label(label="Mariehamn",x=0.3,y=0.2, fontfamily = family) +
  draw_label(label="Polygons - Åland Islands",x=0.3,y=0.95, fontfamily = family,size=40) +
  draw_line(x = c(0.345, 0.467),y = c(0.2, 0.385),color = "darkred", size = 0.5)

# save final plot
ragg::agg_png("/Users/federica/Documents/R/R_general_resources/30DayMapChallenge/day3_polygons/polygons.png",
              res = 320, width = 12, height = 8, units = "in")
final
dev.off()