将鼠标悬停在强制布局d3中的节点上时连接的链接线动画

var graph = {
    "nodes": [{
            "name": "1",
            "rating": 90,
            "id": 2951,
            "x": 90,
            "y": 50,
           "fixed": true
        }, {
            "name": "2",
            "rating": 80,
            "id": 654654,
            "x": 50,
            "y": 50,
            "fixed": true
        }, {
            "name": "3",
            "rating": 80,
            "id": 6546544,
            "x": 50,
            "y": 90,
            "fixed": true
        },

    ],
    "links": [{
            "source": 1,
            "target": 0,
            "value": 6,
            "label": "publishedOn"
        }, {
            "source": 1,
            "target": 2,
            "value": 6,
            "label": "publishedOn"
        }, {
            "source": 1,
            "target": 0,
            "value": 4,
            "label": "containsKeyword"
        },

    ]
}


var margin = {
    top: -5,
    right: -5,
    bottom: -5,
    left: -5
};
var width = 500 - margin.left - margin.right,
    height = 400 - margin.top - margin.bottom;

var color = d3.scale.category20();

var force = d3.layout.force()
    .charge(-200)
    .linkDistance(50)
    .size([width + margin.left + margin.right, height + margin.top + margin.bottom]);

var zoom = d3.behavior.zoom()
     .scaleExtent([.1, 1])
    .on("zoom", zoomed);
 
var drag = d3.behavior.drag()
    .origin(function(d) {
        return d;
    })
    .on("dragstart", dragstarted)
    .on("drag", dragged)
    .on("dragend", dragended);


var svg = d3.select("#map").append("svg")
    .attr("width", width + margin.left + margin.right)
    .attr("height", height + margin.top + margin.bottom)
    .append("g")
    .attr("transform", "translate(" + margin.left + "," + margin.right + ")").call(zoom);

var rect = svg.append("rect")
    .attr("width", width)
    .attr("height", height)
    .style("fill", "none")
    .style("pointer-events", "all");

var container = svg.append("g");

//d3.json('http://blt909.free.fr/wd/map2.json', function(error, graph) {



force
    .nodes(graph.nodes)
    .links(graph.links)
    .start();

var movement = 200;

var link = container.append("g")
   // .attr("class", "links")
    .selectAll(".link")
    .data(graph.links)
    .enter().append("line")
    .attr("class", "link")
    .style("stroke-width", function(d) {
        return Math.sqrt(d.value);
    })
    //.attr("transform", function(d) {
    //    return "translate(" + movement + "," + 0 + ")";
    //})
.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; })
; 


var node = container
    .selectAll(".node").append("g")
    
    .data(graph.nodes)
    .enter().append("g")

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

node.append("circle")

    .attr("r", function(d) {
        return d.weight * 2 + 12;
    })
    .style("fill", function(d) {
        return color(1 / d.rating);
    })
    //.attr("transform", function(d) {
    //    return "translate(" + movement + "," + 0 + ")";
    //})
//.call(drag)
; //Here you move the nodes

force.on("tick", tick);

function tick(){
//force.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("transform", function(d) {
        //Here i create a node radius so it doesnt go offscreen
        var nodeRadius = d.weight * 2 + 12
        
        //here I do checks to see if it goes offscreen
        if(d.x<= nodeRadius){
           d.x = nodeRadius;
           }
        if(d.y<= nodeRadius){
           d.y = nodeRadius;
           }7
        if(d.x>width - nodeRadius){
           d.x = width - nodeRadius;
           }
        if(d.y>height - nodeRadius){
           d.y = height - nodeRadius;
           }
        
        return "translate(" + d.x + "," + d.y + ")";
        
    });
}

var linkedByIndex = {};
graph.links.forEach(function(d) {
    linkedByIndex[d.source.index + "," + d.target.index] = 1;
});

function isConnected(a, b) {
    return linkedByIndex[a.index + "," + b.index] || linkedByIndex[b.index + "," + a.index];
}

node.on("mouseover", function(d) {
    link.attr("stroke-dasharray", 10 + " " + 10)
    .attr("stroke-dashoffset", 500)
    .transition()
    .duration(2000)
    .ease("linear")
    .attr("stroke-dashoffset", 0);
    
    
    node.classed("node-active", function(o) {
        thisOpacity = isConnected(d, o) ? true : false;
        this.setAttribute('fill-opacity', thisOpacity);
        return thisOpacity;
    });

    link.classed("link-active", function(o) {
        return o.source === d || o.target === d ? true : false;
    });

    d3.select(this).classed("node-active", true);
    d3.select(this).select("circle").transition()
        .duration(750)
        .attr("r", (d.weight * 2 + 12) * 1.5);
})

.on("mouseout", function(d) {

  link.attr("stroke-dasharray", 0).attr("stroke-dashoffset", 0);
    node.classed("node-active", false);
    link.classed("link-active", false);

    d3.select(this).select("circle").transition()
        .duration(750)
        .attr("r", d.weight * 2 + 12);
});


function dottype(d) {
    d.x = +d.x;
    d.y = +d.y;
    return d;
}

function zoomed() {
    container.attr("transform", "translate(" + d3.event.translate + ")scale(" + d3.event.scale + ")");
}

function dragstarted(d) {
    d3.event.sourceEvent.stopPropagation();

    d3.select(this).classed("dragging", true);
    force.start();
}

function dragged(d) {
    force.stop();
    d3.select(this).attr("cx", d.x = d3.event.x).attr("cy", d.y = d3.event.y);
    
     
    tick(); 

}

function dragended(d) {
    d.fixed = true;

    //d3.select(this).classed("dragging", false);
    tick();
}

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

.node-active{
  stroke: #555;
  stroke-width: 1.5px;
}

.link {
  stroke: #555;
  stroke-opacity: .3;
}

.link-active {
  stroke-opacity: 1;
}

.overlay {
  fill: none;
  pointer-events: all;
}

#map{
    border: 2px #555 dashed;
    width:500px;
    height:400px;
}

<link href="https://code.jquery.com/ui/1.10.4/themes/black-tie/jquery-ui.css" rel="stylesheet"/>
<script src="https://code.jquery.com/ui/1.11.3/jquery-ui.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.4.11/d3.min.js"></script>
<div id="map"></div>