geom_sankey: geom_sankey

In thisplot: Utility Functions for Plotting

geom_sankey

Description

Creates a sankey plot which visualize flows between nodes. Each observation needs to have a 'x' aesthetic as well as a 'next_x' column which declares where that observation should flow. Also each observation should have a 'node' and a 'next_node' aesthetic which provide information about which group in the y-direction. By default each row of the data frame is counted to calculate the size of flows. A manual flow value can be added with the 'value' aesthetic.

Usage

geom_sankey(
  mapping = NULL,
  data = NULL,
  position = "identity",
  na.rm = FALSE,
  show.legend = NA,
  space = NULL,
  type = "sankey",
  width = 0.1,
  smooth = 8,
  inherit.aes = TRUE,
  ...
)

Arguments

mapping	Provide you own mapping. Both x and y need to be numeric.
data	Provide you own data.
position	Change position.
na.rm	Remove missing values.
show.legend	Show legend in plot.
space	Space between nodes in the y-direction.
type	Either 'sankey' or 'alluvial'.
width	Width of nodes.
smooth	How much smooth should the curve have? More means steeper curve.
inherit.aes	Should the geom inherit aesthetics.
...	Other arguments to be passed to the geom.

Value

A ggplot layer.

Aesthetics

geom_sankey understand the following aesthetics (required aesthetics are in bold):

- **x0** - **y0** - **a** - **b** - **angle** - m1 - m2 - color - fill - size - linetype - alpha - lineend

Examples

dat <- data.frame(
  Group = c("A", "A", "B", "B", "C"),
  Type = c("X", "Y", "X", "Y", "X")
)
long <- make_long(dat, Group, Type)
ggplot2::ggplot(
  long,
  ggplot2::aes(
    x = x,
    next_x = next_x,
    node = node,
    next_node = next_node,
    fill = node
  )
) +
  geom_sankey() +
  theme_sankey()

thisplot documentation built on March 7, 2026, 5:07 p.m.