d3.js - 带边界的 d3 v4 强制布局

Question

我正在尝试在 d3 v4 中创建一个 forceSimulation，它不会让节点漂浮在 svg 的边界之外，就像这个例子在 d3 v3 中一样 https://bl.ocks.org/mbostock/1129492 .

在 simulation.on("tick", ticked) 中尝试了一些不同的东西都无济于事。我的codePen在下面。关于如何实现这一目标的任何想法？

https://codepen.io/mtsvelik/pen/rzxVrE

    //Read the data from the mis element 
    var graph = document.getElementById('json').innerHTML;
    graph = JSON.parse(graph);
    render(graph);  



    function render(graph){

    // Dimensions of sunburst.
    var radius = 6;

    var maxValue = d3.max(graph.links, function(d, i, data) {
        return d.value;
    });

    //sub-in max-value from
    d3.select("div").html('<form class="force-control" ng-if="formControl">Link threshold 0 <input type="range" id="thersholdSlider" name="points" value="0" min="0" max="'+ maxValue +'">'+ maxValue +'</form>');

    document.getElementById("thersholdSlider").onchange = function() {threshold(this.value);};

    var svg = d3.select("svg");
    var width = svg.attr("width");
    var height = svg.attr("height");


    console.log(graph);
    var graphRec = JSON.parse(JSON.stringify(graph)); //Add this line       
    //graphRec = graph; //Add this line         
    console.log(graphRec);

    var simulation = d3.forceSimulation()
            .force("link", d3.forceLink().id(function(d) { return d.id; }))
            .force("charge", d3.forceManyBody().strength(Number(-1000 + (1.25*graph.links.length))))  //default force is -30, making weaker to increase size of chart
            .force("center", d3.forceCenter(width / 2, height / 2));

    var link = svg.append("g")
              .attr("class", "links")
            .selectAll("line")
            .data(graph.links)
            .enter().append("line")
              .attr("class", "link")
              .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("class", "node")
              .attr("r", radius)
              .attr("fill", function(d) { return d.color; })
              .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);

    console.log(link.data(graph.links));


    function ticked() {
            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;
        }



    function threshold(thresh) {
            thresh = Number(thresh);
            graph.links.splice(0, graph.links.length);
                for (var i = 0; i < graphRec.links.length; i++) {
                    if (graphRec.links[i].value > thresh) {graph.links.push(graphRec.links[i]);}
                }

            console.log(graph.links);
            /*var threshold_links = graph.links.filter(function(d){ return (d.value > thresh);});
            console.log(graph.links);

            restart(threshold_links);*/
            restart();


        }


    //Restart the visualisation after any node and link changes
//  function restart(threshold_links) {
    function restart() {    

            //DATA JOIN 
            //link = link.data(threshold_links);
            link = link.data(graph.links);    
            console.log(link); 

            //EXIT
            link.exit().remove();
            console.log(link);

            // ENTER - https://bl.ocks.org/colbenkharrl/21b3808492b93a21de841bc5ceac4e47
            // Create new links as needed.  
            link = link.enter().append("line")
            .attr("class", "link")
              .attr("stroke-width", function(d) { return Math.sqrt(d.value); }).merge(link);            
            console.log(link);


            // DATA JOIN
            node = node.data(graph.nodes);

            /*
            // EXIT
            node.exit().remove();

            // ENTER
            node = node.enter().append("circle")
                .attr("class", "node")
                .attr("r", radius)
                .attr("fill", function(d) {return d.color;})
                .call(d3.drag()
                  .on("start", dragstarted)
                  .on("drag", dragged)
                  .on("end", dragended)
                )
                .merge(node);

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

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

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

            simulation.alphaTarget(0.3).restart();
        }

    }

Answer 1

在tick函数中限制节点移出边界:

    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)));
  })
  //now update the links.

工作代码here