ggguides

GitHub stars R-CMD-check Codecov test coverage License: MIT

Simplified legend and guide alignment for ggplot2.

Installation

# install.packages("pak")
pak::pak("gcol33/ggguides")

Overview

ggguides provides one-liner functions for common legend operations in ggplot2:

Examples

Position Helpers

library(ggplot2)
library(ggguides)

p <- ggplot(mtcars, aes(mpg, wt, color = factor(cyl))) +
  geom_point(size = 3) +
  labs(color = "Cylinders")

legend_left() / legend_right()

Position with proper alignment (sets justification and box.just together):

p + legend_left()
p + legend_right()

legend_top() / legend_bottom()

Horizontal layout with optional plot alignment:

p + legend_top()
p + legend_bottom()

# Align to full plot (useful with titles)
p + labs(title = "My Title") + legend_top(align_to = "plot")

legend_inside()

Position inside the plot using coordinates or shortcuts:

# Using shortcuts
p + legend_inside(position = "topright")
p + legend_inside(position = "bottomleft")

# Using coordinates
p + legend_inside(x = 0.95, y = 0.95, just = c("right", "top"))

# With custom styling
p + legend_inside(position = "center", background = "grey95", border = "grey50")

legend_none()

Remove the legend entirely:

p + legend_none()

Style Helpers

legend_style()

Comprehensive styling in one call:

# Change font size - affects both title and labels
p + legend_style(size = 14)

# Change font family
p + legend_style(family = "serif")
p + legend_style(family = "mono")

# Combine size and family
p + legend_style(size = 14, family = "serif")

# Full styling with title emphasis
p + legend_style(
  size = 12,
  title_size = 14,
  title_face = "bold",
  key_width = 1.5,
  background = "grey95",
  background_color = "grey70",
  margin = 0.3
)

legend_wrap()

Wrap legend entries into columns or rows:

ggplot(mpg, aes(displ, hwy, color = class)) +
  geom_point() +
  legend_wrap(ncol = 2)

# Or by rows
ggplot(mpg, aes(displ, hwy, color = class)) +
  geom_point() +
  legend_wrap(nrow = 2)

legend_reverse()

Reverse legend entry order:

p + legend_reverse()

Multiple Legends

When a plot has multiple aesthetics, control each legend separately:

legend_hide() / legend_select()

Hide specific legends or keep only certain ones:

# Plot with multiple aesthetics
p <- ggplot(mtcars, aes(mpg, wt, color = factor(cyl), size = hp)) +
  geom_point() +
  labs(color = "Cylinders", size = "Horsepower")

# Hide the size legend
p + legend_hide(size)

# Keep only the colour legend
p + legend_select(colour)

Position legends separately

Use the by parameter to position legends independently:

# Colour legend on left, size legend at bottom
p +
  legend_left(by = "colour") +
  legend_bottom(by = "size")

Style legends separately

Apply different styles to different legends:

p +
  legend_style(title_face = "bold", by = "colour") +
  legend_style(size = 10, by = "size")

legend_order_guides()

Control the display order of multiple legends:

# Size legend first, then colour
p + legend_order_guides(size = 1, colour = 2)

Patchwork Integration

collect_legends()

Collect legends from patchwork compositions:

library(patchwork)

p1 <- ggplot(mtcars, aes(mpg, wt, color = factor(cyl))) +
  geom_point() + labs(title = "Plot 1")
p2 <- ggplot(mtcars, aes(mpg, hp, color = factor(cyl))) +
  geom_point() + labs(title = "Plot 2")

# Without collection (duplicate legends)
p1 | p2

# With collection
collect_legends(p1 | p2)

# Position at bottom
collect_legends(p1 | p2, position = "bottom")

Height Spanning

For stacked plots, use span = TRUE to make the legend span the full height. Using different plot heights makes the spanning behavior more visible:

library(patchwork)

p3 <- ggplot(mtcars, aes(mpg, disp, color = factor(cyl))) +
  geom_point() + labs(title = "Plot 3")

# Stack with different heights: 4, 2, 1
stacked <- (p1 / p2 / p3) + plot_layout(heights = c(4, 2, 1))

# Default: legend centered
collect_legends(stacked, position = "right")

# With spanning: legend fills full height
gt <- collect_legends(stacked, position = "right", span = TRUE)
grid::grid.draw(gt)

Row-Specific Attachment

Attach the legend to specific rows instead of spanning all:

# Attach legend to row 1 only (the tallest plot)
gt <- collect_legends(stacked, position = "right", span = 1)
grid::grid.draw(gt)

# Attach legend to rows 1 and 2
gt <- collect_legends(stacked, position = "right", span = 1:2)
grid::grid.draw(gt)

Combining Functions

Functions compose naturally:

ggplot(mpg, aes(displ, hwy, color = class)) +
  geom_point() +
  legend_left() +
  legend_style(size = 12, title_face = "bold", background = "grey95")

ggplot(mpg, aes(displ, hwy, color = class)) +
  geom_point() +
  legend_wrap(ncol = 2) +
  legend_bottom()

cowplot / Base Grid Support

ggguides also works without patchwork for cowplot users or anyone using base grid:

get_legend()

Extract a legend as a standalone grob:

p <- ggplot(mtcars, aes(mpg, wt, color = factor(cyl))) +
  geom_point() + labs(color = "Cylinders")

# Extract the legend
leg <- get_legend(p)

# Use with cowplot::plot_grid() or grid::grid.draw()
grid::grid.draw(leg)

shared_legend()

Combine plots with a shared legend (no patchwork required):

p1 <- ggplot(mtcars, aes(mpg, wt, color = factor(cyl))) +
  geom_point() + labs(title = "Plot 1", color = "Cylinders")
p2 <- ggplot(mtcars, aes(mpg, hp, color = factor(cyl))) +
  geom_point() + labs(title = "Plot 2", color = "Cylinders")
p3 <- ggplot(mtcars, aes(mpg, disp, color = factor(cyl))) +
  geom_point() + labs(title = "Plot 3", color = "Cylinders")

# Side-by-side with shared legend
gt <- shared_legend(p1, p2, ncol = 2, position = "right")
grid::grid.draw(gt)

# Stacked with legend at bottom
gt <- shared_legend(p1, p2, p3, ncol = 1, position = "bottom")
grid::grid.draw(gt)

# 2x2 grid
gt <- shared_legend(p1, p2, p3, p1, ncol = 2, nrow = 2, position = "right")
grid::grid.draw(gt)

All ggguides styling functions (legend_style(), legend_wrap(), etc.) work on individual plots regardless of layout package.

License

MIT