A little thing to try to show how to make a top down collapsable tree map with d3 v4. It’s not a great example and has a number of extraneous functions as I was messing around just trying to learn how to use this layout a little bit.
Mostly copied from: https://bl.ocks.org/d3noob/43a860bc0024792f8803bba8ca0d5ecd
But hopefully I’m going to hack it so show how to max and or min heapify an array of numerical data. But transitions in d3 are hard…
But for a great and maybe more useful viz that works and has a decent explanation of how to use a heap data structure check out http://www.benfrederickson.com/heap-visualization/
<!DOCTYPE html>
<html>
<head>
<link rel="stylesheet" href="./style.css" />
<script src="https://d3js.org/d3.v4.js"></script>
</head>
<body>
<div id="heap">
</div>
<script src="heaper.js"></script>
</body>
</html>
var numbs = [ 4, 7, 8, 2, 3, 1, 23 ]
var margin = {top: 20, right: 90, bottom: 30, left: 90},
width = 960 - margin.left - margin.right,
height = 500 - margin.top - margin.bottom;
var i = 0,
duration = 750,
root;
var counter = 0;
var treeData = {};
var svg = d3.select("#heap")
.append("svg")
.attr("width", width + margin.right + margin.left)
.attr("height", height + margin.top + margin.bottom)
var g = svg.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
var tree = d3.tree()
.size([width, height]);
function buildHeap(inData){
var newsource = {name: inData[0], children: getChildren(0, inData) }
// console.log('dl', newsource)
root = d3.hierarchy(newsource, function(d) { return d.children; });
root.x0 = 0;
root.y0 = width/2;
update(root)
}
// just leaving this global so i can mess with it in the console
var nodes;
function update(source){
// root = d3.hierarchy(newsource, function(d) { return d.children; });
var treeData = tree(root)
nodes = treeData.descendants();
var links = treeData.descendants().slice(1);
// ****************** Nodes section ***************************
// Update the nodes...
var node = g.selectAll('g.node')
.data(nodes, function(d) {return d.id || (d.id = ++i); });
// Enter any new modes at the parent's previous position.
var nodeEnter = node.enter().append('g')
.attr('class', 'node')
.attr("transform", function(d) {
return "translate(" + source.x0 + "," + source.y0 + ")";
})
.on('click', click);
// Add Circle for the nodes
nodeEnter.append('circle')
.attr('class', 'node')
.attr('r', 1e-6)
.style("fill", function(d) {
return d._children ? "lightsteelblue" : "#fff";
});
// Add labels for the nodes
nodeEnter.append('text')
.attr("dy", ".35em")
.attr("x", function(d) {
return d.children || d._children ? -13 : 13;
})
.attr("text-anchor", function(d) {
return d.children || d._children ? "end" : "start";
})
.text(function(d) { return d.data.name; });
// UPDATE
var nodeUpdate = nodeEnter.merge(node);
// Transition to the proper position for the node
nodeUpdate.transition()
.duration(duration)
.attr("transform", function(d) {
return "translate(" + d.x + "," + d.y + ")";
});
// Update the node attributes and style
nodeUpdate.select('circle.node')
.attr('r', 10)
.style("fill", function(d) {
return d._children ? "lightsteelblue" : "#fff";
})
.attr('cursor', 'pointer');
// Remove any exiting nodes
var nodeExit = node.exit().transition()
.duration(duration)
.attr("transform", function(d) {
return "translate(" + source.x + "," + source.y + ")";
})
.remove();
// On exit reduce the node circles size to 0
nodeExit.select('circle')
.attr('r', 1e-6);
// On exit reduce the opacity of text labels
nodeExit.select('text')
.style('fill-opacity', 1e-6);
// ****************** links section ***************************
// Update the links...
var link = g.selectAll('path.link')
.data(links, function(d) { return d.id; });
// Enter any new links at the parent's previous position.
var linkEnter = link.enter().insert('path', "g")
.attr("class", "link")
.attr('d', function(d){
var o = {y: source.y0, x: source.x0}
return diagonal(o, o)
});
// UPDATE
var linkUpdate = linkEnter.merge(link);
// Transition back to the parent element position
linkUpdate.transition()
.duration(duration)
.attr('d', function(d){ return diagonal(d, d.parent) });
// Remove any exiting links
var linkExit = link.exit().transition()
.duration(duration)
.attr('d', function(d) {
var o = {x: source.x, y: source.y}
return diagonal(o, o)
})
.remove();
// Store the old positions for transition.
nodes.forEach(function(d, i){
// console.log(d)
d.x0 = d.x;
d.y0 = d.y;
});
console.log(nodes[0])
//nodes[0].data.children = nodes[0].data._children;
//nodes[0].data._children = null;
}
// Takes an index and an array and finds all the children.
// returns an array which can be added to children of the root node to
// make a json thing which can be used to make a d3.hierarchy();
function getChildren(i, arr) {
var childs = [];
if( arr[i+1+ i] ){
childs[0] = {name: arr[i*2+1], children: []}
if( arr[i+i+2] ){
// console.log(arr[i+1+ i], arr[i+i+2])
childs[1] = {name: arr[i * 2 + 2], children:[]} ;
}
}
var nextin = i * 2 + 1;
if(arr[nextin*2+1]){
// console.log('more children')
childs[0].children = getChildren(nextin, arr)
childs[0]._children = null;
if( arr[nextin*2 + 2 ]){
childs[1].children = getChildren(nextin+1, arr);
childs[1]._children = null;
}
}
return childs;
}
// not called but kind of what I might use to annimate the swap thing while
// balancing binary heaps
function expandChildren(index, chi){
setTimeout(function () {
//buildHeap([ 4, 3, 2, 9, 14, 29] );
console.log('hooho', nodes)
if(nodes[index].children === null){
nodes[0].children = [nodes[0]._children[chi]]
}
else{
console.log( typeof nodes[0]. children)
nodes[index].children.push(nodes[index]._children[1])
}
// .h(nodes[0]._children[0]);
//nodes[0]._children ;
// console.log(nodes[index])
update(nodes[index])
if(chi < 1){
expandChildren(0, 1)
}
}, 3000);
}
//expandChildren(0, 0);
// Creates a curved (diagonal) path from parent to the child nodes
// switched around all the x's and y's from orig so it's verticle
function diagonal(s, d) {
//console.log('in diag and s = ', s);
//console.log('d = ', d)
path = `M ${s.x} ${s.y}
C ${(s.x + d.x) / 2} ${s.y},
${(s.x + d.x) / 2} ${d.y},
${d.x} ${d.y}`
return path;
}
// Toggle children on click.
function click(d) {
// use the following to superficially change the text of the node.
// this.getElementsByTagName('text')[0].textContent = "clicked all over"
if (d.children) {
d._children = d.children;
d.children = null;
} else {
d.children = d._children;
d._children = null;
}
update(d);
}
// will make all the children null and store the real vals in _children
function collapse(d) {
if(d.children) {
d._children = d.children
d.children = null;
d._children.forEach(collapse)
}
}
buildHeap( numbs )
.node {
cursor: pointer;
}
.node circle {
fill: #fff;
stroke: steelblue;
stroke-width: 1.5px;
}
.node text {
font: 10px sans-serif;
}
.link {
fill: none;
stroke: #ccc;
stroke-width: 1.5px;
}