--- /dev/null
+d3.sankey = function() {
+ var sankey = {},
+ nodeWidth = 24,
+ nodePadding = 8,
+ size = [1, 1],
+ nodes = [],
+ links = [];
+
+ sankey.nodeWidth = function(_) {
+ if (!arguments.length) return nodeWidth;
+ nodeWidth = +_;
+ return sankey;
+ };
+
+ sankey.nodePadding = function(_) {
+ if (!arguments.length) return nodePadding;
+ nodePadding = +_;
+ return sankey;
+ };
+
+ sankey.nodes = function(_) {
+ if (!arguments.length) return nodes;
+ nodes = _;
+ return sankey;
+ };
+
+ sankey.links = function(_) {
+ if (!arguments.length) return links;
+ links = _;
+ return sankey;
+ };
+
+ sankey.size = function(_) {
+ if (!arguments.length) return size;
+ size = _;
+ return sankey;
+ };
+
+ sankey.layout = function(iterations) {
+ computeNodeLinks();
+ computeNodeValues();
+ computeNodeBreadths();
+ computeNodeDepths(iterations);
+ computeLinkDepths();
+ return sankey;
+ };
+
+ sankey.relayout = function() {
+ computeLinkDepths();
+ return sankey;
+ };
+
+ sankey.link = function() {
+ var curvature = .5;
+
+ function link(d) {
+ var x0 = d.source.x + d.source.dx,
+ x1 = d.target.x,
+ xi = d3.interpolateNumber(x0, x1),
+ x2 = xi(curvature),
+ x3 = xi(1 - curvature),
+ y0 = d.source.y + d.sy + d.dy / 2,
+ y1 = d.target.y + d.ty + d.dy / 2;
+ return "M" + x0 + "," + y0
+ + "C" + x2 + "," + y0
+ + " " + x3 + "," + y1
+ + " " + x1 + "," + y1;
+ }
+
+ link.curvature = function(_) {
+ if (!arguments.length) return curvature;
+ curvature = +_;
+ return link;
+ };
+
+ return link;
+ };
+
+ // Populate the sourceLinks and targetLinks for each node.
+ // Also, if the source and target are not objects, assume they are indices.
+ function computeNodeLinks() {
+ nodes.forEach(function(node) {
+ node.sourceLinks = [];
+ node.targetLinks = [];
+ });
+ links.forEach(function(link) {
+ var source = link.source,
+ target = link.target;
+ if (typeof source === "number") source = link.source = nodes[link.source];
+ if (typeof target === "number") target = link.target = nodes[link.target];
+ source.sourceLinks.push(link);
+ target.targetLinks.push(link);
+ });
+ }
+
+ // Compute the value (size) of each node by summing the associated links.
+ function computeNodeValues() {
+ nodes.forEach(function(node) {
+ node.value = Math.max(
+ d3.sum(node.sourceLinks, value),
+ d3.sum(node.targetLinks, value)
+ );
+ });
+ }
+
+ // Iteratively assign the breadth (x-position) for each node.
+ // Nodes are assigned the maximum breadth of incoming neighbors plus one;
+ // nodes with no incoming links are assigned breadth zero, while
+ // nodes with no outgoing links are assigned the maximum breadth.
+ function computeNodeBreadths() {
+ var remainingNodes = nodes,
+ nextNodes,
+ x = 0;
+
+ while (remainingNodes.length) {
+ nextNodes = [];
+ remainingNodes.forEach(function(node) {
+ node.x = x;
+ node.dx = nodeWidth;
+ node.sourceLinks.forEach(function(link) {
+ nextNodes.push(link.target);
+ });
+ });
+ remainingNodes = nextNodes;
+ ++x;
+ }
+
+ //
+ moveSinksRight(x);
+ scaleNodeBreadths((size[0] - nodeWidth) / (x - 1));
+ }
+
+ function moveSourcesRight() {
+ nodes.forEach(function(node) {
+ if (!node.targetLinks.length) {
+ node.x = d3.min(node.sourceLinks, function(d) { return d.target.x; }) - 1;
+ }
+ });
+ }
+
+ function moveSinksRight(x) {
+ nodes.forEach(function(node) {
+ if (!node.sourceLinks.length) {
+ node.x = x - 1;
+ }
+ });
+ }
+
+ function scaleNodeBreadths(kx) {
+ nodes.forEach(function(node) {
+ node.x *= kx;
+ });
+ }
+
+ function computeNodeDepths(iterations) {
+ var nodesByBreadth = d3.nest()
+ .key(function(d) { return d.x; })
+ .sortKeys(d3.ascending)
+ .entries(nodes)
+ .map(function(d) { return d.values; });
+
+ //
+ initializeNodeDepth();
+ resolveCollisions();
+ for (var alpha = 1; iterations > 0; --iterations) {
+ relaxRightToLeft(alpha *= .99);
+ resolveCollisions();
+ relaxLeftToRight(alpha);
+ resolveCollisions();
+ }
+
+ function initializeNodeDepth() {
+ var ky = d3.min(nodesByBreadth, function(nodes) {
+ return (size[1] - (nodes.length - 1) * nodePadding) / d3.sum(nodes, value);
+ });
+
+ nodesByBreadth.forEach(function(nodes) {
+ nodes.forEach(function(node, i) {
+ node.y = i;
+ node.dy = node.value * ky;
+ });
+ });
+
+ links.forEach(function(link) {
+ link.dy = link.value * ky;
+ });
+ }
+
+ function relaxLeftToRight(alpha) {
+ nodesByBreadth.forEach(function(nodes, breadth) {
+ nodes.forEach(function(node) {
+ if (node.targetLinks.length) {
+ var y = d3.sum(node.targetLinks, weightedSource) / d3.sum(node.targetLinks, value);
+ node.y += (y - center(node)) * alpha;
+ }
+ });
+ });
+
+ function weightedSource(link) {
+ return center(link.source) * link.value;
+ }
+ }
+
+ function relaxRightToLeft(alpha) {
+ nodesByBreadth.slice().reverse().forEach(function(nodes) {
+ nodes.forEach(function(node) {
+ if (node.sourceLinks.length) {
+ var y = d3.sum(node.sourceLinks, weightedTarget) / d3.sum(node.sourceLinks, value);
+ node.y += (y - center(node)) * alpha;
+ }
+ });
+ });
+
+ function weightedTarget(link) {
+ return center(link.target) * link.value;
+ }
+ }
+
+ function resolveCollisions() {
+ nodesByBreadth.forEach(function(nodes) {
+ var node,
+ dy,
+ y0 = 0,
+ n = nodes.length,
+ i;
+
+ // Push any overlapping nodes down.
+ nodes.sort(ascendingDepth);
+ for (i = 0; i < n; ++i) {
+ node = nodes[i];
+ dy = y0 - node.y;
+ if (dy > 0) node.y += dy;
+ y0 = node.y + node.dy + nodePadding;
+ }
+
+ // If the bottommost node goes outside the bounds, push it back up.
+ dy = y0 - nodePadding - size[1];
+ if (dy > 0) {
+ y0 = node.y -= dy;
+
+ // Push any overlapping nodes back up.
+ for (i = n - 2; i >= 0; --i) {
+ node = nodes[i];
+ dy = node.y + node.dy + nodePadding - y0;
+ if (dy > 0) node.y -= dy;
+ y0 = node.y;
+ }
+ }
+ });
+ }
+
+ function ascendingDepth(a, b) {
+ return a.y - b.y;
+ }
+ }
+
+ function computeLinkDepths() {
+ nodes.forEach(function(node) {
+ node.sourceLinks.sort(ascendingTargetDepth);
+ node.targetLinks.sort(ascendingSourceDepth);
+ });
+ nodes.forEach(function(node) {
+ var sy = 0, ty = 0;
+ node.sourceLinks.forEach(function(link) {
+ link.sy = sy;
+ sy += link.dy;
+ });
+ node.targetLinks.forEach(function(link) {
+ link.ty = ty;
+ ty += link.dy;
+ });
+ });
+
+ function ascendingSourceDepth(a, b) {
+ return a.source.y - b.source.y;
+ }
+
+ function ascendingTargetDepth(a, b) {
+ return a.target.y - b.target.y;
+ }
+ }
+
+ function center(node) {
+ return node.y + node.dy / 2;
+ }
+
+ function value(link) {
+ return link.value;
+ }
+
+ return sankey;
+};
Code Review / portal.git / blobdiff