Scientific software engineer with master degrees in both computer science and remote sensing working on data analysis and visualization.
csv = `source,target,value
A,B,50
A,C,50
C,D,250
E,C,200`
svg = {
const svg = d3.select(DOM.svg(width, height));
const defs = svg.append("defs");
// Add definitions for all of the linear gradients.
const gradients = defs
.selectAll("linearGradient")
.data(graph.links)
.join("linearGradient")
.attr("id", d => d.gradient.id);
gradients
.append("stop")
.attr("offset", 0.0)
.attr("stop-color", d => d.source.color);
gradients
.append("stop")
.attr("offset", 1.0)
.attr("stop-color", d => d.target.color);
// Add a g.view for holding the sankey diagram.
const view = svg
.append("g")
.classed("view", true)
.attr("transform", `translate(${margin}, ${margin})`);
// Define the nodes.
const nodes = view
.selectAll("rect.node")
.data(graph.nodes)
.join("rect")
.classed("node", true)
.attr("id", d => `node-${d.index}`)
.attr("x", d => d.x0)
.attr("y", d => d.y0)
.attr("width", d => d.x1 - d.x0)
.attr("height", d => Math.max(1, d.y1 - d.y0))
.attr("fill", d => d.color)
.attr("opacity", 0.9);
// Add titles for node hover effects.
nodes.append("title").text(d => `${d.name}\n${format(d.value)}`);
// Add text labels.
view
.selectAll("text.node")
.data(graph.nodes)
.join("text")
.classed("node", true)
.attr("x", d => d.x1)
.attr("dx", 6)
.attr("y", d => (d.y1 + d.y0) / 2)
.attr("dy", "0.35em")
.attr("fill", "black")
.attr("text-anchor", "start")
.attr("font-size", 10)
.attr("font-family", "Arial, sans-serif")
.text(d => d.name)
.filter(d => d.x1 > width / 2)
.attr("x", d => d.x0)
.attr("dx", -6)
.attr("text-anchor", "end");
// Define the gray links.
const links = view
.selectAll("path.link")
.data(graph.links)
.join("path")
.classed("link", true)
.attr("d", sankey.sankeyLinkHorizontal())
.attr("stroke", "black")
.attr("stroke-opacity", 0.1)
.attr("stroke-width", d => Math.max(1, d.width))
.attr("fill", "none");
// Add <title> hover effect on links.
links
.append("title")
.text(
d => `${d.source.name} ${arrow} ${d.target.name}\n${format(d.value)}`
);
// Define the default dash behavior for colored gradients.
function setDash(link) {
let el = view.select(`#${link.path.id}`);
let length = el.node().getTotalLength();
el.attr("stroke-dasharray", `${length} ${length}`).attr(
"stroke-dashoffset",
length
);
}
const gradientLinks = view
.selectAll("path.gradient-link")
.data(graph.links)
.join("path")
.classed("gradient-link", true)
.attr("id", d => d.path.id)
.attr("d", sankey.sankeyLinkHorizontal())
.attr("stroke", d => d.gradient)
.attr("stroke-opacity", 0)
.attr("stroke-width", d => Math.max(1, d.width))
.attr("fill", "none")
.each(setDash);
function branchAnimate(node) {
let links = view.selectAll("path.gradient-link").filter(link => {
return node.sourceLinks.indexOf(link) !== -1;
});
let nextNodes = [];
links.each(link => {
nextNodes.push(link.target);
});
links
.attr("stroke-opacity", 0.5)
.transition()
.duration(duration)
.ease(d3.easeLinear)
.attr("stroke-dashoffset", 0)
.on("end", () => {
nextNodes.forEach(node => {
branchAnimate(node);
});
});
}
function branchClear() {
gradientLinks.transition();
gradientLinks.attr("stroke-opactiy", 0).each(setDash);
}
nodes.on("mouseover", branchAnimate).on("mouseout", branchClear);
return svg.node();
}
graph = {
const graph = layout(energy2);
graph.nodes.forEach(node => {
node.color = color(node.index / graph.nodes.length);
});
graph.links.forEach(link => {
link.gradient = DOM.uid("gradient");
link.path = DOM.uid("path");
});
return graph;
}
layout = sankey.sankey()
.size(size)
.nodePadding(nodePadding)
.nodeWidth(nodeWidth)
format = (value) => {
let f = d3.format(",.0f");
return f(value) + " TWh";
}
color = (value) => {
return d3.interpolateRainbow(value);
}
csvData = d3.csvParse(await csv, d3.autoType)
// Recreate same object as energy object used in the original notebook (ugly code sorry)
energy2 = {
var a = {};
for (var i = 0; i < csvData.length; i++) {
a[csvData[i].source] = 1;
a[csvData[i].target] = 1;
}
var nodes = [];
var listNodes = Object.keys(a);
for (var i = 0; i < listNodes.length; i++) {
nodes.push({ name: listNodes[i] });
}
var links = [];
for (var i = 0; i < csvData.length; i++) {
links.push({
source: listNodes.indexOf(csvData[i].source),
target: listNodes.indexOf(csvData[i].target),
value: csvData[i].value
});
}
return { nodes, links };
}
size = [width - 2 * margin, height - 2 * margin]
height = 600
margin = 10
nodeWidth = 20
nodePadding = 10
duration = 250
arrow = "\u2192"
d3 = require("d3@5.9")
sankey = require("d3-sankey@0.12")
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