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ggguides

CRAN status CRAN downloads Monthly downloads R-CMD-check Codecov test coverage License: MIT

Simple, Intuitive Legend Control for ggplot2

The ggguides package provides one-liner functions for common legend operations in ggplot2. Instead of memorizing theme() arguments and guide specifications, use readable functions like legend_left(), legend_style(), and legend_inside() to position, style, and customize legends with minimal code.

Quick Start

library(ggplot2)
library(ggguides)

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

# Position legends
p + legend_left()
p + legend_inside("topright")

# Style legends
p + legend_style(size = 14, title_face = "bold")

# Combine freely
p + legend_bottom() + legend_style(background = "grey95")

Statement of Need

Legend customization in ggplot2 often requires verbose theme() calls with non-obvious argument names (legend.position, legend.justification, legend.box.just), and guide specifications scattered across guides() and scale_*() functions. Common tasks like positioning a legend inside the plot, styling the legend box, or managing multiple legends require looking up documentation repeatedly.

ggguides addresses this by providing:

  • Readable function names that describe what they do (legend_left(), legend_inside(), legend_reverse())
  • Sensible defaults that handle related settings together (e.g., legend_left() sets position, justification, and box alignment)
  • Consistent API across positioning, styling, and multi-legend operations
  • Patchwork integration for multi-panel figures with shared legends

Installation

install.packages("ggguides")

Or install the development version from GitHub:

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

Features

Position Functions

  • legend_left() / legend_right(): Side positioning with proper alignment
  • legend_top() / legend_bottom(): Horizontal layout with optional plot alignment
  • legend_inside(): Position inside plot using coordinates or shortcuts ("topright", "bottomleft", etc.)
  • legend_none(): Remove legend entirely

Style Functions

  • legend_style(): Comprehensive styling (size, font, background, borders, margins)
  • legend_wrap(): Wrap entries into columns or rows
  • legend_reverse(): Reverse entry order
  • legend_order(): Reorder legend entries
  • legend_keys(): Customize key appearance
  • colorbar_style(): Style continuous color legends

Multiple Legend Control

  • legend_hide() / legend_select(): Show/hide specific legends by aesthetic
  • legend_order_guides(): Control display order of multiple legends
  • legend_merge() / legend_split(): Combine or separate legend entries
  • by parameter: Apply any function to specific aesthetics only

Multi-Panel Support

  • collect_legends(): Collect legends from patchwork compositions
  • collect_axes(): Collect axes from patchwork compositions
  • shared_legend(): Combine plots with shared legend (no patchwork required)
  • get_legend(): Extract legend as standalone grob

Usage 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.

Documentation

Support

"Software is like sex: it's better when it's free." — Linus Torvalds

I'm a PhD student who builds R packages in my free time because I believe good tools should be free and open. I started these projects for my own work and figured others might find them useful too.

If this package saved you some time, buying me a coffee is a nice way to say thanks. It helps with my coffee addiction.

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License

MIT (see the LICENSE.md file)

Citation

@software{ggguides,
  author = {Colling, Gilles},
  title = {ggguides: Simplified Legend and Guide Alignment for ggplot2},
  year = {2025},
  url = {https://CRAN.R-project.org/package=ggguides},
  doi = {10.32614/CRAN.package.ggguides}
}

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Simplified Legend and Guide Alignment for ggplot2

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