d3-multichord

This is a modification of d3-chord to enable another dimension of data to be shown between nodes.

Circular layout for visualizing relationships or network flows with multiple types.

Installing

If you use NPM, npm install d3-multichord. Otherwise, download the latest release.

API Reference

This module is an adaptation of d3-chord. Only the changes relevant to the multichord version are included here.

# d3.multichord() <>

Constructs a new multichord layout with the default settings.

# chord(matrix) <>

Computes the chord layout for the specified three-dimensional matrix of shape n×n×m, where the matrix represents the directed flow amongst a network (a complete digraph) of n nodes, and links between nodes are classified into m categories. The given matrix must be an array of length n, where each element matrix[i] is an array of n numbers, where each matrix[i][j] represents the flow from the ith node in the network to the jth node, and each element matrix[i][j][k] is a an array of length m that represents the value of the flow from each of m categories. Each number within matrix[i][j][k] must be nonnegative, though it can be zero if there is no flow from node i to node j for that category.

Sample data from the US Census Migration Data by Nativity Example:

var matrix = [
    [[0,0,0],[49,0,6],[236,1,18],[135,11,6]],
    [[37,1,9],[0,0,0],[230,9,19],[94,3,0]],
    [[295,6,24],[282,8,25],[0,0,0],[323,18,29]],
    [[181,5,16],[107,13,13],[195,6,26],[0,0,0]]
];

The chords array also defines a secondary array of length n, chords.groups, where each group represents the combined inflow and outflow for node i, corresponding to the sum of the elements in matrix[i][0 … n - 1][0 … m - 1], and is an object with the following properties:

• startAngle - the start angle in radians
• endAngle - the end angle in radians
• value - in: the total incoming flow value for node i; out: the total outgoing flow value for node i
• index - the node index i