Introduction

The aim of this mini project is make some fun cartograms of Puerto Rico!

library(tidyverse)
library(broom)
library(sf)
library(ggthemes)
library(ggplot2)
library(cartogram)
library(tweenr)    
library(gganimate)
library(sp)

Loading data

The first dataset I am using is Geodata regarding Puerto Rico. This data was very hard to find.

districts <- st_read("map.json") # load as sf object

## Reading layer `map' from data source 
##   `C:\Users\jodyh\Desktop\islands_projects\pr_pop\map.json' using driver `GeoJSON'
## Simple feature collection with 78 features and 13 fields
## Geometry type: MULTIPOLYGON
## Dimension:     XY
## Bounding box:  xmin: -67.95181 ymin: 17.88264 xmax: -64.99986 ymax: 18.51597
## Geodetic CRS:  WGS 84

Next is loading the population data

population <- read.csv("data.csv") %>% as_tibble() # load as tibble for binding

Now I have to prepare the data and calculate the cartogram

toplot_base <- left_join(districts, population, by = c("id_1" = "id")) %>%
  st_transform(crs = 3857) # load with a mercator project
toplot_base$X2019 <- as.double(toplot_base$X2019) # make sure is a number

toplot2019 <- toplot_base %>% select(c("id",
                                       "X2019",
                                       "geometry"))
toplot_plain <- toplot_base %>% select(c("id",
                                       "X2019",
                                       "geometry"))
toplot_end <- toplot_plain # create the frames

toplot_plain$frame <- "a"
toplot2019$frame <- "b"
toplot_end$frame <- "c" # give the frames identities

toplot2019 <- toplot2019 %>% cartogram_cont(weight = "X2019") # calculate 

data <- rbind(toplot_plain, toplot2019, toplot_end)

Making Plots

Now I make the plots, one static, one animated

ggplot(toplot2019, aes(fill = X2019)) + # load data into plot
  geom_sf(size = 0) + # remove borders
  theme_void() +
  scale_fill_viridis_b(option = "B", # format scale and legend
                       breaks = c(50000, 100000, 150000, 200000),
                       labels = c("50000", "100000", "150000", "200000"),
                       guide = guide_legend(title = "Population",
                                            keyheight = unit(3, units = "mm"),
                                            keywidth=unit(12, units = "mm"),
                                            label.position = "bottom",
                                            title.position = 'top', nrow=1)) + 
  theme(
    legend.position = "bottom", # put key at the bottom
    plot.background = element_rect(fill = "#D2D2CF", color = NA),
    panel.background = element_rect(fill = "#D2D2CF", color = NA), 
    legend.background = element_rect(fill = "#D2D2CF", color = NA), 
  ) +
  coord_sf()

Now I make the animated plot using gganimate

p <- ggplot(data, aes(fill = X2019)) +
  geom_sf(size = 0) + # remove borders
  theme_void() +
  scale_fill_viridis_b(option = "B", # format scale and legend
                       breaks = c(50000, 100000, 150000, 200000),
                       labels = c("50000", "100000", "150000", "200000"),
                       guide = guide_legend(title = "Population",
                                            keyheight = unit(3, units = "mm"),
                                            keywidth=unit(12, units = "mm"),
                                            label.position = "bottom",
                                            title.position = 'top', nrow=1)) + 
  theme(legend.position = "bottom", # put key at the bottom
        plot.background = element_rect(fill = "#D2D2CF", color = NA),
        panel.background = element_rect(fill = "#D2D2CF", color = NA),
        legend.background = element_rect(fill = "#D2D2CF", color = NA)) +
  coord_sf() +
  transition_states(frame,
                    transition_length = 2,
                    state_length = 1) + # code frames
  ease_aes('sine-in-out')

anim_save(animation = p,
          "cart.gif",
          renderer = gifski_renderer(),
          res = 1080,
          width = 3,
          height = 2,
          units = "in") # save as gif