How to avoid overlapping legends for multiple geom_point layers in ggplot2

I'm trying to create a chart with 2 geom_points and a geom_text_repel layer. When I display my legend, the geom_points overlap. The main data points should be represented as empty circles, while the "region"-specific points should be filled circles. Additionally, the points corresponding to regions are not displayed correctly in the legend.

library(ggplot2)
library(ggrepel)
library(stringr)

set.seed(123)
data_filtered <- data.frame(
    evolution = runif(15, -10, 10),
    tauxpourmille = runif(15, 0, 100),
    faits = sample(1:100, 15, replace = TRUE),
    Code.région = sample(letters[1:3], 15, replace = TRUE),
    Code.département = sample(LETTERS[1:5], 15, replace = TRUE)
)

evol_tpm_reg_filtered <- data.frame(
    evolution_reg = runif(3, -10, 10),
    tauxpourmille = runif(3, 0, 100),
    Code.région = letters[1:3]
)

x_label <- "Évolution"
y_label <- "Taux pour mille"

region_colors <- c("red", "blue", "green")

ggplot(data_filtered, aes(x = evolution, y = tauxpourmille, size = faits, color = factor(Code.région))) +
    geom_point(shape = 1, stroke = 1.3, alpha = 0.6, show.legend = TRUE) +
    geom_text_repel(aes(label = Code.département),
                    family = "sans",
                    box.padding = 3,
                    size = 5,
                    min.segment.length = 0,
                    force = 20,
                    max.overlaps = 50,
                    segment.size = 0.5,
                    show.legend = FALSE) +
    geom_point(data = evol_tpm_reg_filtered, aes(x = evolution_reg, y = tauxpourmille, color = factor(Code.région)),
               size = 5, shape = 16, show.legend = TRUE) +
    labs(x = str_wrap(x_label, width = 90),
         y = str_wrap(y_label, width = 35),
         color = "Region",
         size = "Faits") +
    theme_minimal() +
    scale_color_manual(values = region_colors) +
    scale_size_area(max_size = 30,
                    breaks = c(min(data_filtered$faits), median(data_filtered$faits), max(data_filtered$faits)),
                    labels = scales::number_format(accuracy = 1)) +
    theme(axis.title.x = element_text(family = "sans", margin = margin(t = 15)),
          axis.title.y = element_text(family = "sans", margin = margin(r = 15)),
          axis.text.x = element_text(face = "bold", family = "sans"),
          axis.text.y = element_text(face = "bold", family = "sans"),
          axis.line.x = element_line(size = 1, color = "lightgray"),
          axis.line.y = element_line(size = 1, color = "lightgray"),
          legend.position = "right") +
    expand_limits(x = range(data_filtered$evolution) + c(-0.5, 0.5) * diff(range(data_filtered$evolution)),
                  y = range(data_filtered$tauxpourmille) + c(-0.5, 0.5) * diff(range(data_filtered$tauxpourmille)))

How can I make sure that the geom_point of “Faits” is an empty circle?

Solution

Simply drop show.legend=TRUE from your geom_points:

library(ggplot2)
library(ggrepel)
library(stringr)

set.seed(123)
data_filtered <- data.frame(
  evolution = runif(15, -10, 10),
  tauxpourmille = runif(15, 0, 100),
  faits = sample(1:100, 15, replace = TRUE),
  Code.région = sample(letters[1:3], 15, replace = TRUE),
  Code.département = sample(LETTERS[1:5], 15, replace = TRUE)
)

evol_tpm_reg_filtered <- data.frame(
  evolution_reg = runif(3, -10, 10),
  tauxpourmille = runif(3, 0, 100),
  Code.région = letters[1:3]
)

x_label <- "Évolution"
y_label <- "Taux pour mille"

region_colors <- c("red", "blue", "green")

ggplot(data_filtered, aes(
  x = evolution, y = tauxpourmille,
  size = faits, color = factor(Code.région)
)) +
  geom_point(shape = 1, stroke = 1.3, alpha = 0.6) +
  geom_text_repel(
    aes(label = Code.département),
    family = "sans",
    box.padding = 3,
    size = 5,
    min.segment.length = 0,
    force = 20,
    max.overlaps = 50,
    segment.size = 0.5,
    show.legend = FALSE
  ) +
  geom_point(
    data = evol_tpm_reg_filtered,
    aes(x = evolution_reg),
    size = 5, shape = 16
  ) +
  labs(
    x = str_wrap(x_label, width = 90),
    y = str_wrap(y_label, width = 35),
    color = "Region",
    size = "Faits"
  ) +
  theme_minimal() +
  scale_color_manual(values = region_colors) +
  scale_size_area(
    max_size = 30,
    breaks = c(
      min(data_filtered$faits),
      median(data_filtered$faits),
      max(data_filtered$faits)
    ),
    labels = scales::number_format(accuracy = 1)
  ) +
  theme(
    axis.title.x = element_text(family = "sans", margin = margin(t = 15)),
    axis.title.y = element_text(family = "sans", margin = margin(r = 15)),
    axis.text.x = element_text(face = "bold", family = "sans"),
    axis.text.y = element_text(face = "bold", family = "sans"),
    axis.line.x = element_line(linewidth = 1, color = "lightgray"),
    axis.line.y = element_line(linewidth = 1, color = "lightgray"),
    legend.position = "right"
  ) +
  expand_limits(
    x = range(data_filtered$evolution) + c(-0.5, 0.5) * diff(range(data_filtered$evolution)),
    y = range(data_filtered$tauxpourmille) + c(-0.5, 0.5) * diff(range(data_filtered$tauxpourmille))
  )