javascript - How to convert to D3's JSON format? -

while following numerous d3 examples, data gets formatted in format given in flare.json:

{  "name": "flare",  "children": [   {    "name": "analytics",    "children": [     {      "name": "cluster",      "children": [       {"name": "agglomerativecluster", "size": 3938},       : 

i have adjacency list follows:

a1 a2 a2 a3 a2 a4 

which want convert above format. currently, doing on server-side there way achieve using d3's functions? found 1 here, approach seems require modification of d3 core library not in favor due maintainability. suggestions?

there's no prescribed format, can redefine data through various accessor functions (such hierarchy.children) , array.map. format quoted convenient representation trees because works default accessors.

the first question whether intend display graph or tree. graphs, data structure defined in terms of nodes , links. trees, input layout root node, may have array of child nodes, , leaf nodes have associated value.

if want display graph, , have list of edges, you'll want iterate on edges in order produce array of nodes , array of links. had file called "graph.csv":

source,target a1,a2 a2,a3 a2,a4 

you load file using d3.csv , produce array of nodes , links:

d3.csv("graph.csv", function(links) {   var nodesbyname = {};    // create nodes each unique source , target.   links.foreach(function(link) {     link.source = nodebyname(link.source);     link.target = nodebyname(link.target);   });    // extract array of nodes map name.   var nodes = d3.values(nodebyname);    function nodebyname(name) {     return nodesbyname[name] || (nodesbyname[name] = {name: name});   } }); 

you can pass these nodes , links force layout visualize graph:

• http://bl.ocks.org/2949937

if want produce tree instead, you'll need different form of data transformation accumulate child nodes each parent.

d3.csv("graph.csv", function(links) {   var nodesbyname = {};    // create nodes each unique source , target.   links.foreach(function(link) {     var parent = link.source = nodebyname(link.source),         child = link.target = nodebyname(link.target);     if (parent.children) parent.children.push(child);     else parent.children = [child];   });    // extract root node.   var root = links[0].source;    function nodebyname(name) {     return nodesbyname[name] || (nodesbyname[name] = {name: name});   } }); 

like so:

• http://bl.ocks.org/2949981