Demonstration of transforming CSV data using D3
For NICAR Beginning D3, 2017
Charts forked from d3indepth‘s block: DOM Manipulation
forked from darlacameron‘s block: 2. Transforming data
forked from darlacameron‘s block: 3. Drawing shapes
forked from anonymous‘s block: Time series chart with real data
forked from jmuyskens‘s block: Multiple time series chart with real data
forked from jmuyskens‘s block: Scatterplot with real data
forked from jmuyskens‘s block: Scatterplot with real data (playing with axis formatting)
var parseTime = d3.timeParse('%a %b %d %H:%M:%S +0000 %Y');
var formatTime = d3.timeFormat('%Y-%m-%d');
var parseFormattedTime = d3.timeParse('%Y-%m-%d');
// this function creates an SVG line chart
var lineChart = function(data){
// set the dimensions and margins of the graph
var margin = {top: 20, right: 20, bottom: 60, left: 50},
width = 950 - margin.left - margin.right,
height = 600 - margin.top - margin.bottom;
// set the ranges
var x = d3.scaleTime().range([0, width]);
var y = d3.scaleLinear().range([height, 0]);
//add a new svg to hold the chart
var svg = d3.select("body").append("svg")
.attr("width", width + margin.left + margin.right)
.attr("height", height + margin.top + margin.bottom)
.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
// Scale the range of the data
x.domain(d3.extent(data, function(d) { return parseTime(d.created_at); }));
y.domain(d3.extent(data, function(d) { return +d.favorite_count; }));
// Add the X Axis
svg.append("g")
.attr('class', 'x axis')
.call(d3.axisBottom(x).tickSize(height).ticks(5));
// Add the Y Axis
svg.append("g")
.attr('class', 'y axis')
.attr('transform', 'translate(' + width + ', 0)')
.call(d3.axisLeft(y).tickSize(width).ticks(7));
// Add a container for the circles
var circles = svg.append('g')
.attr('id', 'circles');
// Add the line path
circles.selectAll("circle")
.data(data)
.enter().append('circle')
.attr('class', function(d) { return 'circle ' + d.source; })
.attr('r', 3)
.attr('cx', function(d) { return x(parseTime(d.created_at)); })
.attr('cy', function(d) { return y(+d.favorite_count); })
// add an annotation
var annotation = svg.append('g')
.attr('transform',
'translate(' + x(parseFormattedTime("2017-01-20")) + ',0)')
// mark inauguration day with a line
annotation.append('line')
.attr('class', 'annotation')
.attr('y1', 0)
.attr('y2', height)
// add a text label to the line
annotation.append('text')
.text('Inauguration day')
.attr('text-anchor', 'end')
.attr('dx', -5)
.attr('dy', 10)
};
<!DOCTYPE html>
<meta charset="utf-8">
<head>
<title>Transforming data</title>
</head>
<style>
body {
font-family: Helvetica Neue, sans-serif;
}
path {
fill: none;
stroke: #aaa;
}
circle {
opacity: 0.5;
}
.axis path {
stroke: none;
}
.axis line {
stroke: #ccc;
}
.axis.x line {
stroke-dasharray: 3px 2px;
}
.circle.Android {
fill: red;
}
line.annotation {
stroke: black;
}
</style>
<body>
<script src="//d3js.org/d3.v4.min.js"></script>
<script src="script.js"></script>
<script>
d3.csv("realdonaldtrumpsinceelection.csv", function(error, data) {
if (error) throw error;
lineChart(data);
});
</script>
</body>
</html>