Question

我正试图找出一种方法来为我的d3.js代码分隔网络图中的节点。当我加载页面时，我不一定关心网络的形状，因为我可以单击并拖动节点以形成我想要的任何形状。但是我不确定在哪里开始尝试将我的节点分开。我四处搜索，我发现的任何东西似乎对我都有用。非常感谢帮助。

以下是加载页面时网络状况的图片： https://i.gyazo.com/919ad4bde39d9fe6a6b6c91548dbcc2f.png

这是我想要的粗略看起来（再次，形状并不重要，我只是希望在初始载荷上有一点距离）： https://i.gyazo.com/fefa29cf861e204bc83f34cbc2d1a17d.png

（我只有8个代表所以我无法上传图片抱歉）

到目前为止，这是我的代码：

<!DOCTYPE html>
<style>

    .links line {
        stroke-opacity: 0.6;
    }

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

</style>

<html lang="en" xmlns="http://www.w3.org/1999/xhtml">

<head>

    <meta charset="utf-8" />
    <title>Group Comments</title>
    <script src="http://d3js.org/d3.v4.min.js"></script>

</head>

<body>
    <p> Not Ready: Group 6 Comments </p>
    <svg width="960" height="600"></svg>
    <script>

        //fetches the svg
        var svg = d3.select("svg"),
            width = +svg.attr("width"),
            height = +svg.attr("height");

        //Sets a color scale
        var color = d3.scaleOrdinal(d3.schemeCategory20);

        var strokeColor = d3.scaleLinear()
            .domain([0, 1, 2])
            .range(["white", "red", "green"]);

        //Creates a force simulation
        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))

        //reads the JSON file
        d3.json("NR6comments.json", function (error, graph) {
            if (error) throw error;

            //sets up the "links" between the nodes
            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) })
                    .attr("stroke", function (d) { return strokeColor(d.value) });

            //sets up the nodes
            var node = svg.append("g")
                .attr("class", "nodes")
                .selectAll("circle")
                .data(graph.nodes)
                .enter().append("circle")
                    .attr("r", 10)
                    .attr("fill", function (d) { return color(d.group); })
                    .call(d3.drag()
                        .on("start", dragstarted)
                        .on("drag", dragged)
                        .on("end", dragended));

            //displays the ID number on a node when hovering over
            node.append("title")
                .text(function (d) { return d.id; });

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

            simulation.force("link")
                .links(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;
        }
    </script>
    <p><a href="likes.html">Likes Chart</a></p>
</body>
</html>

如果我能帮助解决这个问题，我将不胜感激。谢谢！

Answer 1

有不同的方法可以达到你想要的效果。最简单的方法是设置strength方法的manyBody。根据{{3}}：

如果指定了strength，则将strength访问器设置为指定的数字或函数，重新评估每个节点的strength访问器，并返回此force。正值会导致节点相互吸引，类似于重力，而负值会导致节点相互排斥，类似于静电电荷。

由于我无法访问您的数据，因此这是一个简化的演示。第一个版本没有strength，就像您的代码一样：

＆＃13;

var width = 400;
var height = 300;

var svg = d3.select("body")
  .append("svg")
  .attr("width", width)
  .attr("height", height);

var nodes = [{
  name: "foo",
  color: "blue"
}, {
  name: "bar",
  color: "green"
}, {
  name: "baz",
  color: "red"
}, {
  name: "foofoo",
  color: "yellow"
}, {
  name: "foobar",
  color: "blue"
}, {
  name: "foobaz",
  color: "green"
}, {
  name: "barfoo",
  color: "red"
}, {
  name: "barbar",
  color: "yellow"
}, {
  name: "barbaz",
  color: "blue"
}];

var links = [{
  "source": 0,
  "target": 1
}, {
  "source": 0,
  "target": 2
}, {
  "source": 0,
  "target": 3
}, {
  "source": 1,
  "target": 3
}, {
  "source": 1,
  "target": 4
}, {
  "source": 2,
  "target": 5
}, {
  "source": 3,
  "target": 6
}, {
  "source": 1,
  "target": 7
}, {
  "source": 6,
  "target": 8
}, {
  "source": 0,
  "target": 7
}, {
  "source": 2,
  "target": 6
}, {
  "source": 3,
  "target": 8
}];

var simulation = d3.forceSimulation()
  .force("link", d3.forceLink())
  .force("charge", d3.forceManyBody())
  .force("center", d3.forceCenter(width / 2, height / 2));

var link = svg.selectAll(null)
  .data(links)
  .enter()
  .append("line")
  .style("stroke", "#ccc")
  .style("stroke-width", 1);

var node = svg.selectAll(null)
  .data(nodes)
  .enter()
  .append("circle")
  .attr("r", function(d) {
    return d.r = 10;
  })
  .attr("stroke", "gray")
  .attr("stroke-width", "2px")
  .attr("fill", function(d) {
    return d.color
  });

simulation.nodes(nodes);
simulation.force("link")
  .links(links);

simulation.on("tick", function() {

  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
  });

});

＆＃13;

<script src="https://d3js.org/d3.v4.min.js"></script>

＆＃13;

然而，第二个版本将strength设置为负值：

.force("charge", d3.forceManyBody().strength(-500))

这是：

＆＃13;

var width = 400;
var height = 300;

var svg = d3.select("body")
  .append("svg")
  .attr("width", width)
  .attr("height", height);

var nodes = [{
  name: "foo",
  color: "blue"
}, {
  name: "bar",
  color: "green"
}, {
  name: "baz",
  color: "red"
}, {
  name: "foofoo",
  color: "yellow"
}, {
  name: "foobar",
  color: "blue"
}, {
  name: "foobaz",
  color: "green"
}, {
  name: "barfoo",
  color: "red"
}, {
  name: "barbar",
  color: "yellow"
}, {
  name: "barbaz",
  color: "blue"
}];

var links = [{
  "source": 0,
  "target": 1
}, {
  "source": 0,
  "target": 2
}, {
  "source": 0,
  "target": 3
}, {
  "source": 1,
  "target": 3
}, {
  "source": 1,
  "target": 4
}, {
  "source": 2,
  "target": 5
}, {
  "source": 3,
  "target": 6
}, {
  "source": 1,
  "target": 7
}, {
  "source": 6,
  "target": 8
}, {
  "source": 0,
  "target": 7
}, {
  "source": 2,
  "target": 6
}, {
  "source": 3,
  "target": 8
}];

var simulation = d3.forceSimulation()
  .force("link", d3.forceLink())
  .force("charge", d3.forceManyBody().strength(-500))
  .force("center", d3.forceCenter(width / 2, height / 2));

var link = svg.selectAll(null)
  .data(links)
  .enter()
  .append("line")
  .style("stroke", "#ccc")
  .style("stroke-width", 1);

var node = svg.selectAll(null)
  .data(nodes)
  .enter()
  .append("circle")
  .attr("r", function(d) {
    return d.r = 10;
  })
  .attr("stroke", "gray")
  .attr("stroke-width", "2px")
  .attr("fill", function(d) {
    return d.color
  });

simulation.nodes(nodes);
simulation.force("link")
  .links(links);

simulation.on("tick", function() {

  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
  });

});

＆＃13;

<script src="https://d3js.org/d3.v4.min.js"></script>

＆＃13;

增加网络/图表中节点之间的距离

1 个答案: