Function convertToD3Sankey

src/traces/sankey/calc.js:11–146

(trace)

var Colorscale = require('../../components/colorscale');

function convertToD3Sankey(trace) {
    var nodeSpec = trace.node;
    var linkSpec = trace.link;

    var links = [];
    var hasLinkColorArray = isArrayOrTypedArray(linkSpec.color);
    var hasLinkHoverColorArray = isArrayOrTypedArray(linkSpec.hovercolor);
    var hasLinkCustomdataArray = isArrayOrTypedArray(linkSpec.customdata);
    var linkedNodes = {};

    var components = {};
    var componentCount = linkSpec.colorscales.length;
    var i;
    for(i = 0; i < componentCount; i++) {
        var cscale = linkSpec.colorscales[i];
        var specs = Colorscale.extractScale(cscale, {cLetter: 'c'});
        var scale = Colorscale.makeColorScaleFunc(specs);
        components[cscale.label] = scale;
    }

    var maxNodeId = 0;
    for(i = 0; i < linkSpec.value.length; i++) {
        if(linkSpec.source[i] > maxNodeId) maxNodeId = linkSpec.source[i];
        if(linkSpec.target[i] > maxNodeId) maxNodeId = linkSpec.target[i];
    }
    var nodeCount = maxNodeId + 1;
    trace.node._count = nodeCount;

    // Group nodes
    var j;
    var groups = trace.node.groups;
    var groupLookup = {};
    for(i = 0; i < groups.length; i++) {
        var group = groups[i];
        // Build a lookup table to quickly find in which group a node is
        for(j = 0; j < group.length; j++) {
            var nodeIndex = group[j];
            var groupIndex = nodeCount + i;
            if(groupLookup.hasOwnProperty(nodeIndex)) {
                Lib.warn('Node ' + nodeIndex + ' is already part of a group.');
            } else {
                groupLookup[nodeIndex] = groupIndex;
            }
        }
    }

    // Process links
    var groupedLinks = {
        source: [],
        target: []
    };
    for(i = 0; i < linkSpec.value.length; i++) {
        var val = linkSpec.value[i];
        // remove negative values, but keep zeros with special treatment
        var source = linkSpec.source[i];
        var target = linkSpec.target[i];
        if(!(val > 0 && isIndex(source, nodeCount) && isIndex(target, nodeCount))) {
            continue;