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Ch. 5, Fig. 28 - D3.js in Action

This is the code for Chapter 5, Figure 28 from D3.js in Action used to create a word cloud using d3.layout.cloud() (a layout created by Jason Davies that does not come in core D3).

// Word cloud layout by Jason Davies, http://www.jasondavies.com/word-cloud/
// Algorithm due to Jonathan Feinberg, http://static.mrfeinberg.com/bv_ch03.pdf
(function() {
function cloud() {
var size = [256, 256],
text = cloudText,
font = cloudFont,
fontSize = cloudFontSize,
fontStyle = cloudFontNormal,
fontWeight = cloudFontNormal,
rotate = cloudRotate,
padding = cloudPadding,
spiral = archimedeanSpiral,
words = [],
timeInterval = Infinity,
event = d3.dispatch("word", "end"),
timer = null,
cloud = {};
cloud.start = function() {
var board = zeroArray((size[0] >> 5) * size[1]),
bounds = null,
n = words.length,
i = -1,
tags = [],
data = words.map(function(d, i) {
d.text = text.call(this, d, i);
d.font = font.call(this, d, i);
d.style = fontStyle.call(this, d, i);
d.weight = fontWeight.call(this, d, i);
d.rotate = rotate.call(this, d, i);
d.size = ~~fontSize.call(this, d, i);
d.padding = padding.call(this, d, i);
return d;
}).sort(function(a, b) { return b.size - a.size; });
// createMask();
/* var bd = 3000;
while (bd < 4000) {
board[bd] = -1;
bd++
}
*/
function createMask()
{
d3.select("body").append("canvas").attr("id", "maskCanvas")
maskCanvas = document.getElementById('maskCanvas'),
maskCanvas.width = 85;
maskCanvas.height = 85;
maskContext = maskCanvas.getContext('2d');
maskImage = new Image();
maskImage.src = 'mask.png';
maskImage.onload = function(){
maskContext.drawImage(maskImage,0,0,85,85 * maskImage.height / maskImage.width);
maskData = maskContext.getImageData(0,0,85,85).data;
/*
var hh = 0;
while (hh < maskData.length) {
if (hh%4 == 0) {
if (maskData[hh] == 0) {
board[~~(hh/4)] = -1;
}
}
hh++;
}
*/
}
}
if (timer) clearInterval(timer);
timer = setInterval(step, 0);
step();
return cloud;
function step() {
var start = +new Date,
d;
while (+new Date - start < timeInterval && ++i < n && timer) {
d = data[i];
d.x = (size[0] * (Math.random() + .5)) >> 1;
d.y = (size[1] * (Math.random() + .5)) >> 1;
cloudSprite(d, data, i);
if (d.hasText && place(board, d, bounds)) {
tags.push(d);
event.word(d);
if (bounds) cloudBounds(bounds, d);
else bounds = [{x: d.x + d.x0, y: d.y + d.y0}, {x: d.x + d.x1, y: d.y + d.y1}];
// Temporary hack
d.x -= size[0] >> 1;
d.y -= size[1] >> 1;
}
}
if (i >= n) {
cloud.stop();
event.end(tags, bounds);
}
}
}
cloud.stop = function() {
if (timer) {
clearInterval(timer);
timer = null;
}
return cloud;
};
cloud.timeInterval = function(x) {
if (!arguments.length) return timeInterval;
timeInterval = x == null ? Infinity : x;
return cloud;
};
function place(board, tag, bounds) {
var perimeter = [{x: 0, y: 0}, {x: size[0], y: size[1]}],
startX = tag.x,
startY = tag.y,
maxDelta = Math.sqrt(size[0] * size[0] + size[1] * size[1]),
s = spiral(size),
dt = Math.random() < .5 ? 1 : -1,
t = -dt,
dxdy,
dx,
dy;
while (dxdy = s(t += dt)) {
dx = ~~dxdy[0];
dy = ~~dxdy[1];
if (Math.min(dx, dy) > maxDelta) break;
tag.x = startX + dx;
tag.y = startY + dy;
if (tag.x + tag.x0 < 0 || tag.y + tag.y0 < 0 ||
tag.x + tag.x1 > size[0] || tag.y + tag.y1 > size[1]) continue;
// TODO only check for collisions within current bounds.
if (!bounds || !cloudCollide(tag, board, size[0])) {
if (!bounds || collideRects(tag, bounds)) {
var sprite = tag.sprite,
w = tag.width >> 5,
sw = size[0] >> 5,
lx = tag.x - (w << 4),
sx = lx & 0x7f,
msx = 32 - sx,
h = tag.y1 - tag.y0,
x = (tag.y + tag.y0) * sw + (lx >> 5),
last;
for (var j = 0; j < h; j++) {
last = 0;
for (var i = 0; i <= w; i++) {
board[x + i] |= (last << msx) | (i < w ? (last = sprite[j * w + i]) >>> sx : 0);
}
x += sw;
}
delete tag.sprite;
return true;
}
}
}
return false;
}
cloud.words = function(x) {
if (!arguments.length) return words;
words = x;
return cloud;
};
cloud.size = function(x) {
if (!arguments.length) return size;
size = [+x[0], +x[1]];
return cloud;
};
cloud.font = function(x) {
if (!arguments.length) return font;
font = d3.functor(x);
return cloud;
};
cloud.fontStyle = function(x) {
if (!arguments.length) return fontStyle;
fontStyle = d3.functor(x);
return cloud;
};
cloud.fontWeight = function(x) {
if (!arguments.length) return fontWeight;
fontWeight = d3.functor(x);
return cloud;
};
cloud.rotate = function(x) {
if (!arguments.length) return rotate;
rotate = d3.functor(x);
return cloud;
};
cloud.text = function(x) {
if (!arguments.length) return text;
text = d3.functor(x);
return cloud;
};
cloud.spiral = function(x) {
if (!arguments.length) return spiral;
spiral = spirals[x + ""] || x;
return cloud;
};
cloud.fontSize = function(x) {
if (!arguments.length) return fontSize;
fontSize = d3.functor(x);
return cloud;
};
cloud.padding = function(x) {
if (!arguments.length) return padding;
padding = d3.functor(x);
return cloud;
};
return d3.rebind(cloud, event, "on");
}
function cloudText(d) {
return d.text;
}
function cloudFont() {
return "serif";
}
function cloudFontNormal() {
return "normal";
}
function cloudFontSize(d) {
return Math.sqrt(d.value);
}
function cloudRotate() {
return (~~(Math.random() * 6) - 3) * 30;
}
function cloudPadding() {
return 1;
}
// Fetches a monochrome sprite bitmap for the specified text.
// Load in batches for speed.
function cloudSprite(d, data, di) {
if (d.sprite) return;
c.clearRect(0, 0, (cw << 5) / ratio, ch / ratio);
var x = 0,
y = 0,
maxh = 0,
n = data.length;
--di;
while (++di < n) {
d = data[di];
c.save();
c.font = d.style + " " + d.weight + " " + ~~((d.size + 1) / ratio) + "px " + d.font;
var w = c.measureText(d.text + "m").width * ratio,
h = d.size << 1;
if (d.rotate) {
var sr = Math.sin(d.rotate * cloudRadians),
cr = Math.cos(d.rotate * cloudRadians),
wcr = w * cr,
wsr = w * sr,
hcr = h * cr,
hsr = h * sr;
w = (Math.max(Math.abs(wcr + hsr), Math.abs(wcr - hsr)) + 0x1f) >> 5 << 5;
h = ~~Math.max(Math.abs(wsr + hcr), Math.abs(wsr - hcr));
} else {
w = (w + 0x1f) >> 5 << 5;
}
if (h > maxh) maxh = h;
if (x + w >= (cw << 5)) {
x = 0;
y += maxh;
maxh = 0;
}
if (y + h >= ch) break;
c.translate((x + (w >> 1)) / ratio, (y + (h >> 1)) / ratio);
if (d.rotate) c.rotate(d.rotate * cloudRadians);
c.fillText(d.text, 0, 0);
if (d.padding) c.lineWidth = 2 * d.padding, c.strokeText(d.text, 0, 0);
c.restore();
d.width = w;
d.height = h;
d.xoff = x;
d.yoff = y;
d.x1 = w >> 1;
d.y1 = h >> 1;
d.x0 = -d.x1;
d.y0 = -d.y1;
d.hasText = true;
x += w;
}
var pixels = c.getImageData(0, 0, (cw << 5) / ratio, ch / ratio).data,
sprite = [];
while (--di >= 0) {
d = data[di];
if (!d.hasText) continue;
var w = d.width,
w32 = w >> 5,
h = d.y1 - d.y0;
// Zero the buffer
for (var i = 0; i < h * w32; i++) sprite[i] = 0;
x = d.xoff;
if (x == null) return;
y = d.yoff;
var seen = 0,
seenRow = -1;
for (var j = 0; j < h; j++) {
for (var i = 0; i < w; i++) {
var k = w32 * j + (i >> 5),
m = pixels[((y + j) * (cw << 5) + (x + i)) << 2] ? 1 << (31 - (i % 32)) : 0;
sprite[k] |= m;
seen |= m;
}
if (seen) seenRow = j;
else {
d.y0++;
h--;
j--;
y++;
}
}
d.y1 = d.y0 + seenRow;
d.sprite = sprite.slice(0, (d.y1 - d.y0) * w32);
}
}
// Use mask-based collision detection.
function cloudCollide(tag, board, sw) {
sw >>= 5;
var sprite = tag.sprite,
w = tag.width >> 5,
lx = tag.x - (w << 4),
sx = lx & 0x7f,
msx = 32 - sx,
h = tag.y1 - tag.y0,
x = (tag.y + tag.y0) * sw + (lx >> 5),
last;
for (var j = 0; j < h; j++) {
last = 0;
for (var i = 0; i <= w; i++) {
if (((last << msx) | (i < w ? (last = sprite[j * w + i]) >>> sx : 0))
& board[x + i]) return true;
}
x += sw;
}
return false;
}
function cloudBounds(bounds, d) {
var b0 = bounds[0],
b1 = bounds[1];
if (d.x + d.x0 < b0.x) b0.x = d.x + d.x0;
if (d.y + d.y0 < b0.y) b0.y = d.y + d.y0;
if (d.x + d.x1 > b1.x) b1.x = d.x + d.x1;
if (d.y + d.y1 > b1.y) b1.y = d.y + d.y1;
}
function collideRects(a, b) {
return a.x + a.x1 > b[0].x && a.x + a.x0 < b[1].x && a.y + a.y1 > b[0].y && a.y + a.y0 < b[1].y;
}
function archimedeanSpiral(size) {
var e = size[0] / size[1];
return function(t) {
return [e * (t *= .1) * Math.cos(t), t * Math.sin(t)];
};
}
function rectangularSpiral(size) {
var dy = 4,
dx = dy * size[0] / size[1],
x = 0,
y = 0;
return function(t) {
var sign = t < 0 ? -1 : 1;
// See triangular numbers: T_n = n * (n + 1) / 2.
switch ((Math.sqrt(1 + 4 * sign * t) - sign) & 3) {
case 0: x += dx; break;
case 1: y += dy; break;
case 2: x -= dx; break;
default: y -= dy; break;
}
return [x, y];
};
}
// TODO reuse arrays?
function zeroArray(n) {
var a = [],
i = -1;
while (++i < n) a[i] = 0;
return a;
}
var cloudRadians = Math.PI / 180,
cw = 1 << 11 >> 5,
ch = 1 << 11,
canvas,
ratio = 1;
if (typeof document !== "undefined") {
canvas = document.createElement("canvas");
canvas.width = 1;
canvas.height = 1;
ratio = Math.sqrt(canvas.getContext("2d").getImageData(0, 0, 1, 1).data.length >> 2);
canvas.width = (cw << 5) / ratio;
canvas.height = ch / ratio;
} else {
// Attempt to use node-canvas.
canvas = new Canvas(cw << 5, ch);
}
var c = canvas.getContext("2d"),
spirals = {
archimedean: archimedeanSpiral,
rectangular: rectangularSpiral
};
c.fillStyle = c.strokeStyle = "red";
c.textAlign = "center";
if (typeof module === "object" && module.exports) module.exports = cloud;
else (d3.layout || (d3.layout = {})).cloud = cloud;
})();
<html>
<head>
<title>D3 in Action Chapter 5 - Example 12</title>
<meta charset="utf-8" />
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js"></script>
<script src="d3.layout.cloud.js" type="text/JavaScript"></script>
</head>
<style>
svg {
height: 500px;
width: 500px;
border: 1px solid gray;
}
</style>
<body>
<div id="viz">
<svg>
</svg>
</div>
</body>
<footer>
<script>
d3.csv("worddata.csv", function(data) {dataViz(data)});
wordScale=d3.scale.linear().domain([0,100]).range([10,160]).clamp(true);
function dataViz(data) {
randomRotate=d3.scale.linear().domain([0,1]).range([-20,20]);
d3.layout.cloud().size([500, 500])
.words(data)
.rotate(0)
.fontSize(function(d) { return wordScale(d.frequency); })
.on("end", draw)
.start();
function draw(words) {
var wordG = d3.select("svg").append("g").attr("id", "wordCloudG").attr("transform","translate(250,250)");
wordG.selectAll("text")
.data(words)
.enter()
.append("text")
.style("font-size", function(d) { return d.size + "px"; })
.style("opacity", .75)
.attr("text-anchor", "middle")
.attr("transform", function(d) {
return "translate(" + [d.x, d.y] + ")rotate(" + d.rotate + ")";
})
.text(function(d) { return d.text; });
}
}
</script>
</footer>
</html>
text frequency
layout 63
function 61
data 47
return 36
attr 29
chart 28
array 24
style 24
layouts 22
values 22
need 21
nodes 21
pie 21
use 21
figure 20
circle 19
we'll 19
zoom 19
append 17
elements 17
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