时间戳

首页 > 解决方案 > forceManyBody 在 d3 中过滤

javascript - forceManyBody 在 d3 中过滤

问题描述

我将 d3 v4 用于带有节点和箭头的方向图。

基本上我使用这个例子：

但是我删除了拖动“结束”事件，目的是修复拖动节点。

这个想法是，在模拟开始时节点不是固定的，但是在拖动之后，保存固定节点的位置。

但是，我对力量有疑问：

正在做 d3.forceManyBody; 这种方法正在对每个节点施加力。但相反，我希望只对其他节点产生力，所有这些节点都是不固定的。

我怎样才能做到这一点？

//create somewhere to put the force directed graph
var svg = d3.select("svg"),
    width = +svg.attr("width"),
    height = +svg.attr("height");
    
var radius = 15; 

var nodes_data =  [
    {"name": "Lillian", "sex": "F"},
    {"name": "Gordon", "sex": "M"},
    {"name": "Sylvester", "sex": "M"},
    {"name": "Mary", "sex": "F"},
    {"name": "Helen", "sex": "F"},
    {"name": "Jamie", "sex": "M"},
    {"name": "Jessie", "sex": "F"},
    {"name": "Ashton", "sex": "M"},
    {"name": "Duncan", "sex": "M"},
    {"name": "Evette", "sex": "F"},
    {"name": "Mauer", "sex": "M"},
    {"name": "Fray", "sex": "F"},
    {"name": "Duke", "sex": "M"},
    {"name": "Baron", "sex": "M"},
    {"name": "Infante", "sex": "M"},
    {"name": "Percy", "sex": "M"},
    {"name": "Cynthia", "sex": "F"},
    {"name": "Feyton", "sex": "M"},
    {"name": "Lesley", "sex": "F"},
    {"name": "Yvette", "sex": "F"},
    {"name": "Maria", "sex": "F"},
    {"name": "Lexy", "sex": "F"},
    {"name": "Peter", "sex": "M"},
    {"name": "Ashley", "sex": "F"},
    {"name": "Finkler", "sex": "M"},
    {"name": "Damo", "sex": "M"},
    {"name": "Imogen", "sex": "F"}
    ]

//Sample links data 
//type: A for Ally, E for Enemy
var links_data = [
	{"source": "Sylvester", "target": "Gordon", "type":"A" },
    {"source": "Sylvester", "target": "Lillian", "type":"A" },
    {"source": "Sylvester", "target": "Mary", "type":"A"},
    {"source": "Sylvester", "target": "Jamie", "type":"A"},
    {"source": "Sylvester", "target": "Jessie", "type":"A"},
    {"source": "Sylvester", "target": "Helen", "type":"A"},
    {"source": "Helen", "target": "Gordon", "type":"A"},
    {"source": "Mary", "target": "Lillian", "type":"A"},
    {"source": "Ashton", "target": "Mary", "type":"A"},
    {"source": "Duncan", "target": "Jamie", "type":"A"},
    {"source": "Gordon", "target": "Jessie", "type":"A"},
    {"source": "Sylvester", "target": "Fray", "type":"E"},
    {"source": "Fray", "target": "Mauer", "type":"A"},
    {"source": "Fray", "target": "Cynthia", "type":"A"},
    {"source": "Fray", "target": "Percy", "type":"A"},
    {"source": "Percy", "target": "Cynthia", "type":"A"},
    {"source": "Infante", "target": "Duke", "type":"A"},
    {"source": "Duke", "target": "Gordon", "type":"A"},
    {"source": "Duke", "target": "Sylvester", "type":"A"},
    {"source": "Baron", "target": "Duke", "type":"A"},
    {"source": "Baron", "target": "Sylvester", "type":"E"},
    {"source": "Evette", "target": "Sylvester", "type":"E"},
    {"source": "Cynthia", "target": "Sylvester", "type":"E"},
    {"source": "Cynthia", "target": "Jamie", "type":"E"},
    {"source": "Mauer", "target": "Jessie", "type":"E"},
    {"source": "Duke", "target": "Lexy", "type":"A"},
    {"source": "Feyton", "target": "Lexy", "type":"A"},
    {"source": "Maria", "target": "Feyton", "type":"A"},
    {"source": "Baron", "target": "Yvette", "type":"E"},
    {"source": "Evette", "target": "Maria", "type":"E"},
    {"source": "Cynthia", "target": "Yvette", "type":"E"},
    {"source": "Maria", "target": "Jamie", "type":"E"},
    {"source": "Maria", "target": "Lesley", "type":"E"},
    {"source": "Ashley", "target": "Damo", "type":"A"},
    {"source": "Damo", "target": "Lexy", "type":"A"},
    {"source": "Maria", "target": "Feyton", "type":"A"},
    {"source": "Finkler", "target": "Ashley", "type":"E"},
    {"source": "Sylvester", "target": "Maria", "type":"E"},
    {"source": "Peter", "target": "Finkler", "type":"E"},
    {"source": "Ashley", "target": "Gordon", "type":"E"},
    {"source": "Maria", "target": "Imogen", "type":"E"}
    
]


//set up the simulation and add forces  
var simulation = d3.forceSimulation()
					.nodes(nodes_data);
                              
var link_force =  d3.forceLink(links_data)
                        .id(function(d) { return d.name; });            
         
var charge_force = d3.forceManyBody()
    .strength(-100); 
    
var center_force = d3.forceCenter(width / 2, height / 2);  
                      
simulation
    .force("charge_force", charge_force)
    .force("center_force", center_force)
    .force("links",link_force)
 ;

        
//add tick instructions: 
simulation.on("tick", tickActions );

//add encompassing group for the zoom 
var g = svg.append("g")
    .attr("class", "everything");

//draw lines for the links 
var link = g.append("g")
      .attr("class", "links")
    .selectAll("line")
    .data(links_data)
    .enter().append("line")
      .attr("stroke-width", 2)
      .style("stroke", linkColour);        

//draw circles for the nodes 
var node = g.append("g")
        .attr("class", "nodes") 
        .selectAll("circle")
        .data(nodes_data)
        .enter()
        .append("circle")
        .attr("r", radius)
        .attr("fill", circleColour);
 
 
//add drag capabilities  
var drag_handler = d3.drag()
	.on("start", drag_start)
	.on("drag", drag_drag)
	//.on("end", drag_end);	
	
drag_handler(node);


//add zoom capabilities 
var zoom_handler = d3.zoom()
    .on("zoom", zoom_actions);

zoom_handler(svg);     

/** Functions **/

//Function to choose what color circle we have
//Let's return blue for males and red for females
function circleColour(d){
	if(d.sex =="M"){
		return "blue";
	} else {
		return "pink";
	}
}

//Function to choose the line colour and thickness 
//If the link type is "A" return green 
//If the link type is "E" return red 
function linkColour(d){
	if(d.type == "A"){
		return "green";
	} else {
		return "red";
	}
}

//Drag functions 
//d is the node 
function drag_start(d) {
 if (!d3.event.active) simulation.alphaTarget(0.3).restart();
    d.fx = d.x;
    d.fy = d.y;
}

//make sure you can't drag the circle outside the box
function drag_drag(d) {
  d.fx = d3.event.x;
  d.fy = d3.event.y;
}

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

//Zoom functions 
function zoom_actions(){
    g.attr("transform", d3.event.transform)
}

function tickActions() {
    //update circle positions each tick of the simulation 
       node
        .attr("cx", function(d) { return d.x; })
        .attr("cy", function(d) { return d.y; });
        
    //update link positions 
    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; });
} 
<!DOCTYPE html>
<meta charset="utf-8">
<style>

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

.nodes circle {
  stroke: black	;
  stroke-width: 0px;
}

</style>
<svg width="800" height="500"></svg>
<script src="https://d3js.org/d3.v4.min.js"></script>

标签： javascriptd3.js

解决方案

nodes()您可以使用在调用中传递给模拟的节点上的过滤器对受力影响的节点进行过滤。

simulation.nodes(nodes.filter(function(d){return d.dragged === true;}))

如果您希望节点在拖动开始时立即退出力，您可以在将拖动节点设置为 后在拖动开始功能中发生这种.dragged情况true。

推荐阅读