autoplot.markovchain: Plot a Markov chain with ggplot2

In markovchain: Easy Handling Discrete Time Markov Chains

Plot a Markov chain with ggplot2

Description

Creates a ggplot2 representation of a discrete-time Markov chain. Nodes are states and directed edges represent transitions with positive probability. Communicating classes are shown with different node fills.

Usage

autoplot.markovchain(
  object,
  threshold = 0,
  show_probabilities = TRUE,
  digits = 2,
  node_size = 6,
  edge_width = 1,
  type = c("graph", "eigenvalues", "flow", "comparison"),
  steps = 20,
  initial = NULL,
  other = NULL,
  what = c("transition", "stationary"),
  ...
)

Arguments

object	An object of class 'markovchain'.
threshold	Minimum transition probability to display. Defaults to 0.
show_probabilities	Logical; whether to label edges with transition probabilities. Defaults to 'TRUE'.
digits	Number of digits used to format transition probabilities.
node_size	Size of state nodes in the ggplot2 plot.
edge_width	Minimum width multiplier for transition edges.
type	Type of plot: "graph" (default) draws the transition graph; "eigenvalues" draws the eigenvalues of the transition matrix in the complex plane together with the unit circle; "flow" draws the evolution of the distribution over the states, as computed by redistribute; "comparison" compares object with the chains in other.
steps	Number of steps of the "flow" plot. Defaults to 20. Ignored for the other types.
initial	Initial distribution of the "flow" plot, see redistribute. Defaults to the uniform distribution. Ignored for the other types.
other	For type = "comparison": a markovchain object or a (possibly named) list of them, to be compared with object. All chains must be defined on the same set of states, which are matched by name, so their order may differ. Ignored for the other types.
what	For type = "comparison": "transition" (default) draws the transition matrices side by side as heatmaps on a common probability scale; "stationary" compares the stationary distributions as grouped bars (every chain must then be irreducible). Ignored for the other types.
...	Currently unused, reserved for future extensions.

Value

A ggplot object.

Examples

if (requireNamespace("ggplot2", quietly = TRUE)) {
  weather <- matrix(c(0.7, 0.2, 0.1,
                      0.3, 0.4, 0.3,
                      0.2, 0.45, 0.35),
                    nrow = 3, byrow = TRUE,
                    dimnames = list(c("sunny", "cloudy", "rain"),
                                    c("sunny", "cloudy", "rain")))
  mc <- new("markovchain", states = rownames(weather),
            transitionMatrix = weather, name = "Weather")
  ggplot2::autoplot(mc)
  ggplot2::autoplot(mc, type = "eigenvalues")
  ggplot2::autoplot(mc, type = "flow", steps = 10, initial = "rain")

  # compare with a "stickier" version of the same chain
  sticky <- lazyChain(mc, alpha = 0.5)
  sticky@name <- "Lazy weather"
  ggplot2::autoplot(mc, type = "comparison", other = sticky)
  ggplot2::autoplot(mc, type = "comparison", other = sticky,
                    what = "stationary")
}

markovchain documentation built on Oct. 10, 2026, 9:07 a.m.