Gallery: forcegraph

https://github.com/rstudio/r2d3/tree/main/vignettes/gallery/forcegraph

bubbles bullets calendar cartogram chord circlepacking dendogram forcegraph morley population radialtree stackedbars streamgraph sunburst treemap voronoi

r2d3(data = jsonlite::read_json("miserables.json"), d3_version = 4, script = "forcegraph.js")

forcegraph.js

// !preview r2d3 data = jsonlite::read_json("miserables.json"), d3_version = 4

// Based on: https://bl.ocks.org/mbostock/4063570

var color = d3.scaleOrdinal(d3.schemeCategory20);
var radius = 5;

var simulation = d3.forceSimulation()
    .force("link", d3.forceLink().id(function(d) { return d.id; }))
    .force("charge", d3.forceManyBody())
    .force("center", d3.forceCenter(width / 2, height / 2));

r2d3.onRender(function(graph, svg, width, height, options) {
  var link = svg.append("g")
      .attr("class", "links")
    .selectAll("line")
    .data(graph.links)
    .enter().append("line")
      .attr("stroke-width", function(d) { return Math.sqrt(d.value); });

  var node = svg.append("g")
      .attr("class", "nodes")
    .selectAll("circle")
    .data(graph.nodes)
    .enter().append("circle")
      .attr("r", radius)
      .attr("fill", function(d) { return color(d.group); })
      .call(d3.drag()
          .on("start", dragstarted)
          .on("drag", dragged)
          .on("end", dragended));

  node.append("title")
      .text(function(d) { return d.id; });

  simulation
      .nodes(graph.nodes)
      .on("tick", ticked);

  simulation.force("link")
      .links(graph.links);

  function ticked() {
    //constrains the nodes to be within a box
    node
      .attr("cx", function(d) { return d.x = Math.max(radius, Math.min(width - radius, d.x)); })
      .attr("cy", function(d) { return d.y = Math.max(radius, Math.min(height - radius, d.y)); });
      
    link
        .attr("x1", function(d) { return d.source.x; })
        .attr("y1", function(d) { return d.source.y; })
        .attr("x2", function(d) { return d.target.x; })
        .attr("y2", function(d) { return d.target.y; });

    node
        .attr("cx", function(d) { return d.x; })
        .attr("cy", function(d) { return d.y; });
  }
});

function dragstarted(d) {
  if (!d3.event.active) simulation.alphaTarget(0.3).restart();
  d.fx = d.x;
  d.fy = d.y;
}

function dragged(d) {
  d.fx = d3.event.x;
  d.fy = d3.event.y;
}

function dragended(d) {
  if (!d3.event.active) simulation.alphaTarget(0);
  d.fx = null;
  d.fy = null;
}

forcegraph.css

.links line {
  stroke: #999;
  stroke-opacity: 0.6;
}

.nodes circle {
  stroke: #fff;
  stroke-width: 1.5px;
}