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` ````
<!-- container for the visualization -->
<div class="viz"></div>
```

` ````
```

` ````
/* globals d3 */
// dataset describing the consumption of renewable energy at world level
// https://data.worldbank.org/indicator/EG.FEC.RNEW.ZS
const data = [
{
year: '1990',
percentage: 17.0671538947666,
},
{
year: '1991',
percentage: 17.2238189234724,
},
{
year: '1992',
percentage: 17.5843343506126,
},
{
year: '1993',
percentage: 17.5984373876898,
},
{
year: '1994',
percentage: 17.6928633402301,
},
{
year: '1995',
percentage: 17.755347793459,
},
{
year: '1996',
percentage: 17.741819656794,
},
{
year: '1997',
percentage: 17.7683028072844,
},
{
year: '1998',
percentage: 17.9209223918013,
},
{
year: '1999',
percentage: 18.1298420308909,
},
{
year: '2000',
percentage: 17.8993921979056,
},
{
year: '2001',
percentage: 17.6015066667197,
},
{
year: '2002',
percentage: 17.6183731904508,
},
{
year: '2003',
percentage: 17.434098206958,
},
{
year: '2004',
percentage: 17.0972296583476,
},
{
year: '2005',
percentage: 17.0434424770035,
},
{
year: '2006',
percentage: 17.1212606863223,
},
{
year: '2007',
percentage: 16.9083050750164,
},
{
year: '2008',
percentage: 17.0350290849647,
},
{
year: '2009',
percentage: 17.5116086035299,
},
{
year: '2010',
percentage: 17.2551919506048,
},
{
year: '2011',
percentage: 17.2097710318662,
},
{
year: '2012',
percentage: 17.4762365885514,
},
{
year: '2013',
percentage: 17.6990568614625,
},
{
year: '2014',
percentage: 17.8701840419389,
},
{
year: '2015',
percentage: 18.0537549929864,
},
];
// in the .viz container add an svg element following the margin convention
const margin = {
top: 20,
right: 20,
bottom: 20,
left: 20,
};
const width = 700 - (margin.left + margin.right);
const height = 350 - (margin.top + margin.bottom);
const svg = d3
.select('.viz')
.append('svg')
.attr('viewBox', `0 0 ${width + (margin.left + margin.right)} ${height + (margin.top + margin.bottom)}`)
.attr('width', width)
.attr('height', height);
// include the visualization in the nested group
const group = svg
.append('g')
.attr('transform', `translate(${margin.left} ${margin.right})`);
// describe the scales for the line chart
// x-axis: time scale using the years
const xScale = d3
.scaleTime()
.domain([new Date(data[0].year), new Date(data[data.length - 1].year)]) // ! the domain of a time scale describes two date objects
.range([0, width])
.nice();
// y-axis: linear scale using the percentages
const yScale = d3
.scaleLinear()
.domain(d3.extent(data, ({ percentage }) => percentage)) // consider the [minimum, maximum] values
.range([height, 0]) // flip the range considering the top down nature of the SVG coordinate system
.nice();
// describe the line function to plot the data through a path element
// for each data point the line function computes the coordinates based on the input year and percentage
const line = d3
.line()
.x(({ year }) => xScale(new Date(year))) // to obtain the value from the time scale the input needs to be a date object (like the domain)
.y(({ percentage }) => yScale(percentage));
// add a path element using the line function
group
.append('path')
.attr('d', line(data))
.attr('fill', 'none')
.attr('stroke', 'currentColor');
// include the axes based on the defined scales
const xAxis = d3
.axisBottom(xScale);
group
.append('g')
.attr('transform', `translate(0 ${height})`)
.call(xAxis);
const yAxis = d3
.axisLeft(yScale);
group
.append('g')
.call(yAxis);
```

999px

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