A sea of accidents

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<html lang="en">
	<head>
		<meta charset="utf-8">
		<title>Conditional Styling</title>
		<script type="text/javascript" src="https://d3js.org/d3.v3.js"></script>
		<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;
			}

svg {
				background-color: white;
			}

circle:hover {
				fill: orange;
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path {
				stroke: gray;
				stroke-width: 0.5;
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g.highlight path {
				stroke: steelblue;
				stroke-width: 2;
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			.axis path,
			.axis line {
				fill: none;
				stroke: black;
				stroke-width: 1;
				shape-rendering: crispEdges;
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			.axis text {
				font-family: sans-serif;
				font-size: 11px;
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</style>
	</head>
	<body>

<h1>A sea of accidents</h1>

<p>Number of accidents in the Baltic Sea (2004-2013) Source: <a href="https://www.helcom.fi">HELCOM</a></p>

//Dimensions and padding
		var w = 700;
		var h = 600;
		var padding = [ 20, 10, 50, 100 ];  //Top, right, bottom, left

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

var xScale = d3.time.scale()
						.range([ padding[3], w - padding[1] - padding[3] ]);
			
			
		var yScale = d3.scale.linear()
						.range([ padding[0], h - padding[2] ]);

//axis
		var xAxis = d3.svg.axis()
					.scale(xScale)
					.orient("bottom")
					.ticks(15)
					.tickFormat(function(d){
						return dateFormat(d);
					});

var yAxis = d3.svg.axis()
					.scale(yScale)
					.orient("left");

//line generator
		var line = d3.svg.line()
			.x(function(d) {
				return xScale(dateFormat.parse(d.year));
			})
			.y(function(d) {
				return yScale(+d.amount);
			});

//create svg image
		var svg = d3.select("body")
					.append("svg")
					.attr("width", w)
					.attr("height", h);

//load data
		d3.csv("NumberAccidentsYear.csv", function(data) {

var years = ["2004","2005","2006","2007","2008","2009","2010","2011","2012","2013"];

//new empty array for the restructured data
			var dataset = [];

//loop for each row of data
			for (var i = 0; i < data.length; i++) {

//console.log(data.length)

//create new object with this country's name and empty array
				dataset[i] = {
					country: data[i].Country,
					accidents: []
				};

//loop through all the years
				for (var j = 0; j < years.length; j++) {

//console.log(years.length)

//if value is not empty
					if (data[i][years[j]]) {
						//add a new object to the accident array for this country
						dataset[i].accidents.push({
							year: years[j],
							amount: data[i][years[j]]
						});
					}
				}
			}

// console.log(data);
			console.log(dataset);

//set scales domains
			xScale.domain([
				d3.min(years, function(d) {
					return dateFormat.parse(d);
				}),
				d3.max(years, function(d) {
					return dateFormat.parse(d);
				})
			]);

yScale.domain([
				d3.max(dataset, function(d) {
					return d3.max(d.accidents, function(d) {
						return +d.amount;
					});
				}),
				0
			]);

//make group for each country
			var groups = svg.selectAll("g")
							.data(dataset)
							.enter()
							.append("g")
							.classed("highlight", function(d) {

if (d.country == "Sweden" ||
									d.country == "Denmark") {
									return true;
								} else {
									return false;
								}
							});

//append a title with country name (for easy tooltip)
			groups.append("title")
				.text(function(d) {
					return d.country;
				});

//within each group, create a new line/path,
			//binding just the accidents data to each one
			groups.selectAll("path")
				.data(function(d) {
					return [ d.accidents ];
				})
				.enter()
				.append("path")
				.attr("class", "line")
				.attr("d", line)
				.attr("fill", "none")
				.attr("stroke-width", 2);

//Axes
				svg.append("g")
					.attr("class", "x axis")
					.attr("transform", "translate(0," + (h - padding[2]) + ")")
					.call(xAxis);

svg.append("g")
					.attr("class", "y axis")
					.attr("transform", "translate(" + (padding[3]) + ",0)")
					.call(yAxis);

});

</script>

</body>
</html>

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