---
id: 5d8a4cfbe6b6180ed9a1ca39
title: Part 92
challengeType: 0
dashedName: part-92
---

# --description--

Chain a `value` function to `pie` and pass it `d => d.value`. Each piece of data(`d`) will have a `key`(platform) and a `value`(number of followers), you want to return the number of followers here. The pie function will create an array of objects from these values that describe the angles and sizes the pie chart needs.

In a few steps, you will make an array out of your data variable that will be passed to this function.

# --hints--

test-text

```js
assert(
  /const pie = d3\.pie\(\)\s*\.\s*value\s*\(\s*d\s*=>\s*d\.value\s*\)/g.test(
    code
  )
);
```

# --seed--

## --before-user-code--

```html
<!DOCTYPE html>
<html>
  <head>
    <title>D3 Dashboard</title>
    <style>
      body {
        background-color: #ccc;
        padding: 100px 10px;
      }

      .dashboard {
        width: 980px;
        height: 500px;
        background-color: white;
        box-shadow: 5px 5px 5px 5px #888;
        margin: auto;
        display: flex;
        align-items: center;
      }
    </style>
  </head>

  <body>
    <div class="dashboard"></div>
  </body>
</html>
```

## --seed-contents--

```html
<script>
  const data = [ 
    { year: 2012, followers: { twitter: 2594, tumblr:  401, instagram:   83 }},
    { year: 2013, followers: { twitter: 3049, tumblr:  440, instagram:  192 }},
    { year: 2014, followers: { twitter: 3511, tumblr:  415, instagram:  511 }},
    { year: 2015, followers: { twitter: 3619, tumblr:  492, instagram: 1014 }},
    { year: 2016, followers: { twitter: 4046, tumblr:  543, instagram: 2066 }},
    { year: 2017, followers: { twitter: 3991, tumblr:  701, instagram: 3032 }},
    { year: 2018, followers: { twitter: 3512, tumblr: 1522, instagram: 4512 }},
    { year: 2019, followers: { twitter: 3274, tumblr: 1989, instagram: 4715 }},
    { year: 2020, followers: { twitter: 2845, tumblr: 2040, instagram: 4801 }}
  ];
</script>
<script>
  const svgMargin = 70,
    svgWidth = 700,
    svgHeight = 500,
    twitterColor = '#7cd9d1',
    tumblrColor = '#f6dd71',
    instagramColor = '#fd9b98';

  const lineGraph = d3.select('.dashboard')
    .append('svg')
    .attr('width', svgWidth)
    .attr('height', svgHeight);

  const yScale = d3.scaleLinear()
    .domain([0, 5000])
    .range([svgHeight - svgMargin, svgMargin]);

  const xScale = d3.scaleLinear()
    .domain([2012, 2020])
    .range([svgMargin, svgWidth - svgMargin]);

  const yAxis = d3.axisLeft(yScale)
    .ticks(6, '~s');

  const xAxis = d3.axisBottom(xScale)
    .tickFormat(d3.format(''))
    .tickPadding(10);

  lineGraph.append('g')
    .call(yAxis)
    .attr('transform', `translate(${svgMargin}, 0)`)
    .style('font', '10px verdana');

  lineGraph.append('g')
    .call(xAxis)
    .attr('transform', `translate(0, ${svgHeight - svgMargin})`)
    .selectAll('text')
    .style('transform', 'translate(-12px, 0) rotate(-50deg)')
    .style('text-anchor', 'end')
    .style('cursor', 'pointer')
    .style('font', '10px verdana')

  const twitterLine = d3.line()
    .x(d => xScale(d.year))
    .y(d => yScale(d.followers.twitter));

  lineGraph.append('path')
    .attr('d', twitterLine(data))
    .attr('stroke', twitterColor)
    .attr('stroke-width', 3)
    .attr('fill', 'transparent');

  const tumblrLine = d3.line()
    .x(d => xScale(d.year))
    .y(d => yScale(d.followers.tumblr));

  lineGraph.append('path')
    .attr('d', tumblrLine(data))
    .attr('stroke', tumblrColor)
    .attr('stroke-width', 3)
    .attr('fill', 'transparent');

  const instagramLine = d3.line()
    .x(d => xScale(d.year))
    .y(d => yScale(d.followers.instagram));

  lineGraph.append('path')
    .attr('d', instagramLine(data))
    .attr('stroke', instagramColor)
    .attr('stroke-width', 3)
    .attr('fill', 'transparent');
    
  lineGraph.selectAll('twitter-circles')
    .data(data)
    .enter()
    .append('circle')
    .attr('cx', d => xScale(d.year))
    .attr('cy', d => yScale(d.followers.twitter))
    .attr('r', 6)
    .attr('fill', 'white')
    .attr('stroke', twitterColor)
    .style('cursor', 'pointer')

  lineGraph.selectAll('tumblr-circles')
    .data(data)
    .enter()
    .append('circle')
    .attr('cx', d => xScale(d.year))
    .attr('cy', d => yScale(d.followers.tumblr))
    .attr('r', 6)
    .attr('fill', 'white')
    .attr('stroke', tumblrColor)
    .style('cursor', 'pointer')

  lineGraph.selectAll('instagram-circles')
    .data(data)
    .enter()
    .append('circle')
    .attr('cx', d => xScale(d.year))
    .attr('cy', d => yScale(d.followers.instagram))
    .attr('r', 6)
    .attr('fill', 'white')
    .attr('stroke', instagramColor)
    .style('cursor', 'pointer')

  const rightDashboard = d3.select('.dashboard')
    .append('div');

  const pieGraph = rightDashboard.append('svg')
    .attr('width', 200)
    .attr('height', 200)

  const pieArc = d3.arc()
    .outerRadius(100)
    .innerRadius(0);

  const pieColors = d3.scaleOrdinal()  
    .domain(data[8].followers)
    .range([twitterColor, tumblrColor, instagramColor]);

  const pie = d3.pie()



</script>
```

# --solutions--

```html
<script>
  const data = [ 
    { year: 2012, followers: { twitter: 2594, tumblr:  401, instagram:   83 }},
    { year: 2013, followers: { twitter: 3049, tumblr:  440, instagram:  192 }},
    { year: 2014, followers: { twitter: 3511, tumblr:  415, instagram:  511 }},
    { year: 2015, followers: { twitter: 3619, tumblr:  492, instagram: 1014 }},
    { year: 2016, followers: { twitter: 4046, tumblr:  543, instagram: 2066 }},
    { year: 2017, followers: { twitter: 3991, tumblr:  701, instagram: 3032 }},
    { year: 2018, followers: { twitter: 3512, tumblr: 1522, instagram: 4512 }},
    { year: 2019, followers: { twitter: 3274, tumblr: 1989, instagram: 4715 }},
    { year: 2020, followers: { twitter: 2845, tumblr: 2040, instagram: 4801 }}
  ];
</script>
<script>
  const svgMargin = 70,
    svgWidth = 700,
    svgHeight = 500,
    twitterColor = '#7cd9d1',
    tumblrColor = '#f6dd71',
    instagramColor = '#fd9b98';

  const lineGraph = d3.select('.dashboard')
    .append('svg')
    .attr('width', svgWidth)
    .attr('height', svgHeight);

  const yScale = d3.scaleLinear()
    .domain([0, 5000])
    .range([svgHeight - svgMargin, svgMargin]);

  const xScale = d3.scaleLinear()
    .domain([2012, 2020])
    .range([svgMargin, svgWidth - svgMargin]);

  const yAxis = d3.axisLeft(yScale)
    .ticks(6, '~s');

  const xAxis = d3.axisBottom(xScale)
    .tickFormat(d3.format(''))
    .tickPadding(10);

  lineGraph.append('g')
    .call(yAxis)
    .attr('transform', `translate(${svgMargin}, 0)`)
    .style('font', '10px verdana');

  lineGraph.append('g')
    .call(xAxis)
    .attr('transform', `translate(0, ${svgHeight - svgMargin})`)
    .selectAll('text')
    .style('transform', 'translate(-12px, 0) rotate(-50deg)')
    .style('text-anchor', 'end')
    .style('cursor', 'pointer')
    .style('font', '10px verdana')

  const twitterLine = d3.line()
    .x(d => xScale(d.year))
    .y(d => yScale(d.followers.twitter));

  lineGraph.append('path')
    .attr('d', twitterLine(data))
    .attr('stroke', twitterColor)
    .attr('stroke-width', 3)
    .attr('fill', 'transparent');

  const tumblrLine = d3.line()
    .x(d => xScale(d.year))
    .y(d => yScale(d.followers.tumblr));

  lineGraph.append('path')
    .attr('d', tumblrLine(data))
    .attr('stroke', tumblrColor)
    .attr('stroke-width', 3)
    .attr('fill', 'transparent');

  const instagramLine = d3.line()
    .x(d => xScale(d.year))
    .y(d => yScale(d.followers.instagram));

  lineGraph.append('path')
    .attr('d', instagramLine(data))
    .attr('stroke', instagramColor)
    .attr('stroke-width', 3)
    .attr('fill', 'transparent');
    
  lineGraph.selectAll('twitter-circles')
    .data(data)
    .enter()
    .append('circle')
    .attr('cx', d => xScale(d.year))
    .attr('cy', d => yScale(d.followers.twitter))
    .attr('r', 6)
    .attr('fill', 'white')
    .attr('stroke', twitterColor)
    .style('cursor', 'pointer')

  lineGraph.selectAll('tumblr-circles')
    .data(data)
    .enter()
    .append('circle')
    .attr('cx', d => xScale(d.year))
    .attr('cy', d => yScale(d.followers.tumblr))
    .attr('r', 6)
    .attr('fill', 'white')
    .attr('stroke', tumblrColor)
    .style('cursor', 'pointer')

  lineGraph.selectAll('instagram-circles')
    .data(data)
    .enter()
    .append('circle')
    .attr('cx', d => xScale(d.year))
    .attr('cy', d => yScale(d.followers.instagram))
    .attr('r', 6)
    .attr('fill', 'white')
    .attr('stroke', instagramColor)
    .style('cursor', 'pointer')

  const rightDashboard = d3.select('.dashboard')
    .append('div');

  const pieGraph = rightDashboard.append('svg')
    .attr('width', 200)
    .attr('height', 200)

  const pieArc = d3.arc()
    .outerRadius(100)
    .innerRadius(0);

  const pieColors = d3.scaleOrdinal()  
    .domain(data[8].followers)
    .range([twitterColor, tumblrColor, instagramColor]);

  const pie = d3.pie()
    .value(d => d.value);

    
  
</script>
```
