Hi
I found this to be helpful personally. I am a beginner so any feedback would be great!
#import "@preview/cetz:0.3.3": canvas, draw, tree
// Function to draw a graph from an adjacency matrix
#let draw-graph-from-adj-matrix(
adj-matrix,
positions: none,
node_label_fn: i => text(str(i)),
node_color_function: i => white,
node-radius: 0.45,
stroke: (thickness: 1pt), // Changed to dictionary format
) = {
canvas({
import draw: *
// Number of nodes (assuming the matrix is square)
let n = adj-matrix.len()
if n == 0 or adj-matrix.at(0).len() != n {
panic("Adjacency matrix must be square")
}
// Determine node positions
let node-positions = if positions == none {
// Default: Circular layout
let radius = calc.max(2, calc.sqrt(n)) / 2 // Adjust radius based on number of nodes
let center = (0, 0)
let positions = ()
for i in range(n) {
let angle = 360deg / n * i
let x = radius * calc.cos(angle)
let y = radius * calc.sin(angle)
positions.push((x, y))
}
positions
} else {
// Use provided positions
if positions.len() != n {
panic("Number of positions must match number of nodes")
}
positions
}
// Draw edges based on the adjacency matrix
for i in range(n) {
for j in range(i + 1, n) {
// Only upper triangle for undirected graph
if adj-matrix.at(i).at(j) == 1 {
line(node-positions.at(i), node-positions.at(j), stroke: 1pt)
}
}
}
// Draw nodes
for (i, pos) in node-positions.enumerate() {
circle(pos, radius: node-radius, fill: node_color_function(i), stroke: 1pt)
content(pos, node_label_fn(i), anchor: "center")
}
})
}
// Usage
#let adj-matrix-raw = (
(0, 0, 1, 0),
(0, 0, 1, 0),
(1, 1, 0, 1),
(0, 0, 1, 0),
)
$
A = mat(delim:"[", ..#adj-matrix-raw) #
$
#let fig4 = figure(
supplement: [Figure],
draw-graph-from-adj-matrix(adj-matrix-raw),
)