Geometric Index of Unifacial Retouch Zone visualisation with ggplot2

giur-zones-with-ggplot2.R

library(ggplot2)

# coords for vertices of polygons that make the zones
polydata <- rbind(
  data.frame(x = c(0, 0.01, 0.99, 1), 
             y = c(0, 0.25, 0.25, 0), 
             group = "zone 1", 
             fill = "grey80", xc = .5, yc = 0.125),
  data.frame(x = c(0, 0.025, 0.495, 0.495), 
             y = c(-0.01, -0.25, -0.25, -0.01), 
             group = "zone 2", 
             fill = "grey80", xc = .3, yc = -.12),
  data.frame(x = c(0.025, 0.055, 0.495, 0.495), 
             y = c(-0.26, -0.5, -0.5, -0.26), 
             group = "zone 3", 
             fill = "grey80", xc = .3, yc = -.37),
  data.frame(x = c(0.055, 0.085, 0.495, 0.495), 
             y = c(-0.51, -0.75, -0.75, -0.51), 
             group = "zone 4", 
             fill = "grey80", xc = .3, yc = -.61), 
  data.frame(x = c(0.505, 0.505, 0.975, 1), 
             y = c(-0.01, -0.25, -0.25, -0.01), 
             group = "zone 5", 
             fill = "grey80", xc = .71, yc = -.12),
  data.frame(x = c(0.505, 0.505, 0.955, 0.975), 
             y = c(-0.26, -0.5, -0.5, -0.26), 
             group = "zone 6", 
             fill = "grey80", xc = .71, yc = -.37),
  data.frame(x = c(0.505, 0.505, 0.925, 0.955), 
             y = c(-0.51, -0.75, -0.75, -0.51), 
             group = "zone 7", 
             fill = "grey80", xc = .71, yc = -.61),
  data.frame(x = c(0.085, 0.255, 0.755, 0.925), 
             y = c(-0.76, -1, -1, -0.76), 
             group = "zone 8", 
             fill = "grey80", xc = .5, yc = -0.875)
  )

# simulate some values to fill the zones
artefact_data <- 
  data.frame(zone = 1:8,
             GIUR = runif(8))

# join artefact data with polygons for plotting
library(tidyverse)
polydata <- 
  polydata %>% 
  mutate(zone = parse_number(group)) %>% 
  left_join(artefact_data)

# plot the values on the zone map

# avoid overprinting of labels
annotations <- 
  polydata %>% 
  distinct(group, xc, yc)

# draw the plot
ggplot(polydata,
       aes(
         x = x,
         y = y,
         group = group,
         fill = GIUR,
         colour = fill
       )) +
  geom_polygon(alpha = .5) +
  scale_colour_identity() +
  scale_fill_viridis_c(option = "D") +
  annotate(
    'text',
    x = annotations$xc,
    y = annotations$yc,
    label = annotations$group,
    size = 5
  ) +
  ggtitle("GIUR zones with ggplot2") +
  coord_equal() +
  theme_void()