Force simulation of texts on bubble-chart does not work

问题

I have a script in which I make circles and then append text to them. I want to use force simulation so that texts of different circles don't overlap.

The issue that I am currently facing is shown in graph below: (2 red circles on the left have overlapping text)

I used force simuation in my script for texts but nothing happens. I am not getting any error but still the texts are overlapping. I have tried many solution but nothing seems to work.

Following is my script:

 function graph(data){
    //var margin = {top: 30, right: 20, bottom: 30, left: 50}

    var margin = 40,
    width = 600,
    height = 400;

    //   var force = d3.layout.force()
        // .nodes(datas)
        // .size([width, height]);

    simulation = d3.forceSimulation()
        .force("x", d3.forceX())
        .force("y", d3.forceY())
        .force("collide", d3.forceCollide(20)); 

    var xscale = d3.scaleLinear()
        .domain([0, d3.max(data, function (d) {
            return +d.student_percentile;
        })])
        .nice() 
        .range([0, width]);

    var yscale = d3.scaleLinear()
            .domain([0, d3.max(data, function (d) {
                return +d.rank;
            })])
            .nice()
            .range([height, 0]);

    var xAxis = d3.axisBottom().scale(xscale).tickFormat(function(d) {
        return d > 100 ? "Not Available" : d
    });

    var yAxis = d3.axisLeft().scale(yscale);

    var svg = d3.select('.chart')
        .classed("svg-container", true)
        .append('svg')
        .attr('class', 'chart')
        .attr("viewBox", "0 0 680 490")
        .attr("preserveAspectRatio", "xMinYMin meet")
        .classed("svg-content-responsive", true)
        .append("g")
        .attr("transform", "translate(" + margin + "," + margin + ")");

    svg.append("g")
        .attr("class", "y axis")
        .call(yAxis);

    svg.append("g")
      .attr("class", "x axis")
      .attr("transform", "translate(0," + height + ")")
      .call(xAxis);

    var color = d3.scaleOrdinal(d3.schemeCategory10);

    var local = d3.local();
    circles = svg.selectAll(null)
          .data(data)
          .enter()
          .append("circle")
          .attr("cx", width / 2)
          .attr("cy", height / 2)
          .attr("opacity", 0.3)
          .attr("r", 20)
          .style("fill", function(d){
            if(+d.admit_probability <= 40){
                return "red";
            }
            else if(+d.admit_probability > 40 && +d.admit_probability <= 75){
                return "yellow";
            }
            else{
                return "green";
            }
          })
          .attr("cx", function(d) {
            return xscale(+d.student_percentile);
          })
          .attr("cy", function(d) {
            return yscale(+d.rank);
          })
          .on('mouseover', function(d, i) {
            local.set(this, d3.select(this).style("fill"));
            d3.select(this)
              .transition()
              .duration(1000)
              .ease(d3.easeBounce)
              .attr("r", 32)
              .style("cursor", "pointer")
              .attr("text-anchor", "middle");
              var d = this.__data__;
              show_details(d);
            }
           )
          .on('mouseout', function(d, i) {
            d3.select(this).style("fill", local.get(this));
            d3.select(this).transition()
              .style("opacity", 0.3)
              .attr("r", 20)
              .style("cursor", "default")
            .transition()
            .duration(1000)
            .ease(d3.easeBounce);
            remove_details();
          });

    texts = svg.selectAll(null)
      .data(data)
      .enter()
      .append('text')
      .attr("text-anchor", "middle")
      .text(function(d) {
        return d.abbreviation;
      })
      .attr("pointer-events", "none")
      .attr("font-family", "sans-serif")
      .attr("font-size", "12px")
      .attr("fill", "black");

  simulation.nodes(data).on("tick", function(){
        texts.attr("x", function(d) {
             return xscale(+d.student_percentile);
           })
             .attr("y", function(d) {
             return yscale(+d.rank);
           });
    });


  //        force.on("tick", function() {

  //   texts.attr("x", function(d) { return +d.student_percentile; })
  //       .attr("y", function(d) { return +d.rank; });

  // });


    svg.append("text")
        .attr("transform", "translate(" + (width / 2) + " ," + (height + margin) + ")")
        .style("text-anchor", "middle")
        .text("Percentile");

    svg.append("text")
        .attr("transform", "rotate(-90)")
        .attr("y", 0 - margin)
        .attr("x",0 - (height / 2))
        .attr("dy", "1em")
        .style("text-anchor", "middle")
        .text("Rank");

    $('circle').tipsy({ 
        gravity: 'w', 
        html: true, 
        title: function() {
            var d = this.__data__;
            return d.name + '<br/> Rank: ' + d.rank + '<br/> Admit Probaility: ' + d.admit_probability + '%'; 
        }
    });
}

I even tried doing:

 simulation.nodes(data).on("tick", function(){
        texts.attr("x", d3.forceX().x(function(d) {
             return xscale(+d.student_percentile);
           }))
             .attr("y", d3.forceY().y(function(d) {
             return yscale(+d.rank);
           }));
    });

This also does not work.

回答1:

It's very hard to provide a working answer without seeing your data or a minimum running code. But some mistakes are obvious, and this is a general solution:

First, you have to specify the positions you want for the texts in the forceY and forceX functions:

simulation = d3.forceSimulation()
    .force("x", d3.forceX(function(d) {
        return xscale(+d.student_percentile);
    }))
    .force("y", d3.forceY(function(d) {
        return yscale(+d.rank);
    }))
    .force("collide", d3.forceCollide(20)); 

Then, in the tick function, you just use the x and y properties created by the simulation:

simulation.nodes(data).on("tick", function() {
    texts.attr("x", function(d) {
            return d.x;
        })
        .attr("y", function(d) {
            return d.y;
        });
});

来源：https://stackoverflow.com/questions/47094528/force-simulation-of-texts-on-bubble-chart-does-not-work