interactive-vis-course/Week7/multiple_lines_labels_hover.html at gh-pages · arnicas/interactive-vis-course · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
<!DOCTYPE html>
<!-- Modification of an example by Scott Murray from Knight D3 course -->
<html lang="en">
	<head>
		<meta charset="utf-8">
		<title>Line Chart with Multiple Lines</title>
		<style type="text/css">

			body {
				background-color: white;
				font-family: Helvetica, Arial, sans-serif;
			}

			h1 {
				font-size: 24px;
				margin: 0;
			}

			p {
				font-size: 14px;
				margin: 10px 0 0 0;
				width: 700px;
			}

			svg {
				background-color: white;
			}

			path.line {
				fill: none;
				stroke: #ff3399;
				stroke-width: 2px;
				stroke-opacity: 50%;
			}

			#focused {
				stroke: black;
				stroke-width: 2px;
				stroke-opacity: 100%;
			}

			.axis path,
			.axis line {
				fill: none;
				stroke: black;
				stroke-width: 1px;
			}

			.axis text {
				font-family: sans-serif;
				font-size: 11px;
			}

			text.linelabel {
				font-size: 9pt;
				color: gray;
			}

			text.hidden {
				display: none;
			}

			text.bolder {
				font-weight: bolder;
			}


		</style>
	</head>
	<body>

		<h1>CO2 Emissions by Country With Hover</h1>

		<p>Carbon dioxide emissions, 1961-2010. Data not available for the entire period for all countries. Source: <a href="http://data.worldbank.org/indicator/EN.ATM.CO2E.KT?page=6">World Bank</a>, 2014. (Based on a modified example from Scott Murray.)</p>
		<p>This version of the interactive uses the technique in <a href="http://www.nytimes.com/interactive/2016/01/12/upshot/david-bowie-songs-that-fans-are-listening-most-heroes-starman-major-tom.html?_r=0">this NYT David Bowie songs line chart</a> to highlight lines and labels beside the line on mouseover.
		</p>
		<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.6/d3.min.js"></script>
		<script type="text/javascript">


			//Dimensions and padding
			var fullwidth = 700;
			var fullheight = 600;
			var margin = {top: 50, right: 125, bottom: 40, left:80};

			var width = fullwidth - margin.left - margin.right;
			var height = fullheight - margin.top - margin.bottom;


			//Set up date formatting and years
			var dateFormat = d3.time.format("%Y");

			//Set up scales
			var xScale = d3.time.scale()
								.range([ 0, width ]);

			var yScale = d3.scale.linear()
								.range([ 0, height ]);

			//Configure axis generators
			var xAxis = d3.svg.axis()
							.scale(xScale)
							.orient("bottom")
							.ticks(15)
							.tickFormat(function(d) {
								return dateFormat(d);
							})
							.outerTickSize([0])
							.innerTickSize([0]);

			var yAxis = d3.svg.axis()
							.scale(yScale)
							.orient("left")
							.outerTickSize([0]);


			//Configure line generator
			// each line dataset must have a d.year and a d.amount for this to work.
			var line = d3.svg.line()
				.x(function(d) {
					return xScale(dateFormat.parse(d.year));
				})
				.y(function(d) {
					return yScale(+d.amount);
				});


			//Create the empty SVG image
			var svg = d3.select("body")
						.append("svg")
						.attr("width", fullwidth)
						.attr("height", fullheight)
						.append("g")
						.attr("transform", "translate(" + margin.left + "," + margin.top + ")");


			var tooltip = d3.select("body")
      	.append("div")
      	.attr("class", "tooltip");


			//Load data
			d3.csv("data/co2_emissions.csv", function(data) {


				//New array with all the years, for referencing later
				var years = ["1961", "1962", "1963", "1964", "1965", "1966", "1967", "1968", "1969", "1970", "1971", "1972", "1973", "1974", "1975", "1976", "1977", "1978", "1979", "1980", "1981", "1982", "1983", "1984", "1985", "1986", "1987", "1988", "1989", "1990", "1991", "1992", "1993", "1994", "1995", "1996", "1997", "1998", "1999", "2000", "2001", "2002", "2003", "2004", "2005", "2006", "2007", "2008", "2009", "2010"];

				// or you could get this by doing:
				// var years = d3.keys(data[0]).slice(0, 54-4); //

				//Create a new, empty array to hold our restructured dataset
				var dataset = [];

				//Loop once for each row in data
				data.forEach(function (d, i) {

					var myEmissions = [];

					//Loop through all the years - and get the emissions for this data element
					years.forEach(function (y) {

						// If value is not empty
						if (d[y]) {
							//Add a new object to the new emissions data array - for year, amount
							myEmissions.push({
								country: d.countryName, // we can put the country in here too. It won't hurt.
								year: y,
								amount: d[y]  // this is the value for, for example, d["2004"]
 							});
						}

					});

					//Create new object with this country's name and empty array
					// d is the current data row... from data.forEach above.
					dataset.push( {
						country: d.countryName,
						emissions: myEmissions  // we just built this!
						} );

				});

				//Uncomment to log the original data to the console
				// console.log(data);

				//Uncomment to log the newly restructured dataset to the console
				//console.log(dataset);


				//Set scale domains - max and mine of the years
				xScale.domain(
					d3.extent(years, function(d) {
						return dateFormat.parse(d);
					}));

				// max of emissions to 0 (reversed, remember)
				yScale.domain([
					d3.max(dataset, function(d) {
						return d3.max(d.emissions, function(d) {
							return +d.amount;
						});
					}),
					0
				]);


				//Make a group for each country
				var groups = svg.selectAll("g")
					.data(dataset)
					.enter()
					.append("g")
					.on("mouseover", mouseoverFunc)  // putting these on the g nodes gets us a lot!
					.on("mouseout",	mouseoutFunc);


				//Within each group, create a new line/path,
				//binding just the emissions data to each one
				groups.selectAll("path")
					.data(function(d) { // because there's a group with data already...
						return [ d.emissions ]; // it has to be an array for the line function
					})
					.enter()
					.append("path")
					.attr("class", "line")
					.attr("d", line);

			// We're putting the text label at the group level, where the country name was originally.
			groups.append("text")
	      .datum(function(d) {
	      	// this datum move is to access the data at the last data // point and make it easier to refer to below.
	      	return {country: d.country, value: d.emissions[d.emissions.length - 1]};
	      })
	      .attr("transform", function(d) {
	      	// error on some with no d.value - American Samoa, for instance.
	      	if (d.value) {
	      		return "translate(" + xScale(dateFormat.parse(d.value.year)) + "," + yScale(+d.value.amount) + ")";
	      		}
	      	else {
	      		return null;
	      		}
	      	})
	      .attr("x", 3)
	      .attr("dy", 3)
	      .text(function(d) {
	      	return d.country;
	      })
	      .classed("linelabel", true) // basic formatting of labels
	      .classed("hidden", function(d) {
	      	// hide the labels that are too "low" to be interesting
					if (d.value && +d.value.amount > 700000) {
						return false;
					} else {
						return true;
					}
				});

				//Axes
				svg.append("g")
					.attr("class", "x axis")
					.attr("transform", "translate(0," + height + ")")
					.call(xAxis);

				svg.append("g")
					.attr("class", "y axis")
					.call(yAxis);

				//Now we handle the functions for the hover effect:

				function mouseoverFunc(d) {
					// the "this" is the g parent node.  That means we can select it, and then select
					// the child nodes and style the]m as we want for the hover effect!
					d3.select(this).select("path").attr("id", "focused"); // overrides the class
					d3.select(this).select("text").classed("hidden", false);  // show it if "hidden"
					d3.select(this).select("text").classed("bolder", true);
					}

				function mouseoutFunc(d) {
					d3.select(this).select("path").attr("id", null); // remove the focus style
					d3.select(this).select("text").classed("bolder", false); // remove the bolding on label
					// rehide the ones that are in the low numbers
					if (+d.emissions[d.emissions.length-1].amount <= 700000) {
						d3.select(this).select("text").classed("hidden", true);
					}
			  }

			}); // end of data csv


		</script>

	</body>
</html>