cograph (version 2.7.2)

degree_distribution: Degree Distribution Visualization

Description

Creates a histogram or cumulative distribution plot of node degrees. By default, bins are integer-aligned (one bar per degree value) so each bar maps to an exact degree.

Usage

degree_distribution(
  x,
  mode = "all",
  directed = NULL,
  loops = TRUE,
  simplify = "sum",
  cumulative = FALSE,
  breaks = NULL,
  bins = NULL,
  bin_width = NULL,
  normalize = FALSE,
  log = "",
  main = "Degree Distribution",
  xlab = "Degree",
  ylab = NULL,
  col = "steelblue",
  border = "white",
  ...
)

Value

Invisibly returns a list with components:

degree

Named numeric vector of per-node degrees.

table

Table of degree frequencies.

breaks

Breakpoints of the degree histogram.

counts

Bin counts.

proportions

Bin proportions (counts / sum(counts)).

All five components are returned for both the histogram and the cumulative plot; cumulative = TRUE only changes what is drawn.

Arguments

x

Network input: matrix, igraph, network, cograph_network, or tna object.

mode

For directed networks: "all", "in", or "out". Default "all".

directed

Logical or NULL. If NULL (default), auto-detect from matrix symmetry. Set TRUE to force directed, FALSE to force undirected.

loops

Logical. If TRUE (default), keep self-loops. Set FALSE to remove them.

simplify

How to combine multiple edges between the same node pair. Options: "sum" (default), "mean", "max", "min", or FALSE/"none" to keep multiple edges.

cumulative

Logical. If TRUE, show CCDF (complementary cumulative distribution: P(degree >= k)) instead of frequency. Default FALSE.

breaks

Bin specification passed to hist. Can be a numeric vector of breakpoints, a single number giving the number of bins, or a character string naming an algorithm (e.g. "Sturges", "FD", "scott"). Overrides bins and bin_width. Default NULL (auto-detect).

bins

Integer. Approximate number of bins. Overrides bin_width. Default NULL.

bin_width

Numeric. Width of each bin. Default NULL (auto: 1 when the degree range is \(\le 50\), otherwise Freedman-Diaconis).

normalize

Logical. If TRUE, the y-axis shows proportions (bars sum to 1) instead of counts. Default FALSE.

log

Character. Axis log-scaling: "" (none, default), "x", "y", or "xy". Histogram plots apply y-axis log scaling for "y" or "xy"; cumulative plots support x, y, and xy scaling, with "xy" producing a log-log CCDF (standard for power-law inspection).

main

Character. Plot title. Default "Degree Distribution".

xlab

Character. X-axis label. Default "Degree".

ylab

Character. Y-axis label. Default auto-chosen based on normalize and cumulative.

col

Character. Bar/line fill color. Default "steelblue".

border

Character. Bar border color. Default "white".

...

Additional graphical arguments passed to barplot (histogram) or plot (cumulative).

Examples

# Undirected network
adj <- matrix(c(0, 1, 1, 0, 1, 0, 1, 1,
                1, 1, 0, 1, 0, 1, 1, 0), 4, 4, byrow = TRUE)
cograph::degree_distribution(adj)
cograph::degree_distribution(adj, cumulative = TRUE)

# Directed network, in-degree
directed_adj <- matrix(c(0, 1, 0, 0, 0, 0, 1, 0,
                         1, 0, 0, 1, 0, 1, 0, 0), 4, 4, byrow = TRUE)
cograph::degree_distribution(directed_adj, mode = "in")