Parliament charts

Parliament or hemicycle charts are used to visualise the number of seats held by each political party. The chart design is skeuomorphic because it resembles the layout of a parliament.

Ingredients

Data sources

Trafford Council

R packages

Parliament chart

Instructions

Load the necessary R packages.

library(tidyverse) ; library(ggpol)

Create a data frame with the different party names, the number of seats and their associated colours.

df <- tibble(
  party = factor(c("Green", "Liberal Democrats", "Conservative", "Labour"),
                 levels = c("Green", "Liberal Democrats", "Conservative", "Labour")),
  seats = c(3, 4, 20, 36),
  colours = c("#6AB023", "#FAA61A", "#0087DC", "#D32D41"))

Plot the parliament chart.

ggplot(df) + 
  geom_parliament(aes(seats = seats, fill = party), colour = "#FFFFFF") + 
  scale_fill_manual(values = df$colours, labels = df$party,
                    guide = guide_legend(reverse = TRUE)) +
  labs(title = "Trafford Council Local Elections 2019",
       subtitle = "Council Seats",
       fill = NULL) +
  coord_fixed() + 
  theme_void() +
  theme(plot.title = element_text(size = 12, face = "bold", hjust = 0.5),
        plot.subtitle = element_text(hjust = 0.5),
        legend.position = "bottom")

Output the chart as a PNG file.

ggsave("parliament_chart.png", dpi = 300)

Notes

The colour for each party can be found using an online tool like HTML Color Codes which matches the colour in an image to their HEX code.