98 lines
3.7 KiB
Markdown
98 lines
3.7 KiB
Markdown
|
---
|
||
|
|
id: 587d7fa9367417b2b2512bcf
|
||
|
|
title: Dynamically Change the Height of Each Bar
|
||
|
|
required:
|
||
|
|
- src: 'https://cdnjs.cloudflare.com/ajax/libs/d3/4.3.0/d3.min.js'
|
||
|
|
challengeType: 6
|
||
|
|
---
|
||
|
|
|
||
|
|
## Description
|
||
|
|
<section id='description'>
|
||
|
|
The height of each bar can be set to the value of the data point in the array, similar to how the <code>x</code> value was set dynamically.
|
||
|
|
<blockquote>selection.attr("property", (d, i) => {<br> /* <br> * d is the data point value<br> * i is the index of the data point in the array<br> */<br>})</blockquote>
|
||
|
|
</section>
|
||
|
|
|
||
|
|
## Instructions
|
||
|
|
<section id='instructions'>
|
||
|
|
Change the callback function for the <code>height</code> attribute to return the data value times 3.
|
||
|
|
<strong>Note</strong><br>Remember that multiplying all data points by the same constant scales the data (like zooming in). It helps to see the differences between bar values in this example.
|
||
|
|
</section>
|
||
|
|
|
||
|
|
## Tests
|
||
|
|
<section id='tests'>
|
||
|
|
|
||
|
|
```yml
|
||
|
|
tests:
|
||
|
|
- text: The first <code>rect</code> should have a <code>height</code> of 36.
|
||
|
|
testString: 'assert($(''rect'').eq(0).attr(''height'') == ''36'', ''The first <code>rect</code> should have a <code>height</code> of 36.'');'
|
||
|
|
- text: The second <code>rect</code> should have a <code>height</code> of 93.
|
||
|
|
testString: 'assert($(''rect'').eq(1).attr(''height'') == ''93'', ''The second <code>rect</code> should have a <code>height</code> of 93.'');'
|
||
|
|
- text: The third <code>rect</code> should have a <code>height</code> of 66.
|
||
|
|
testString: 'assert($(''rect'').eq(2).attr(''height'') == ''66'', ''The third <code>rect</code> should have a <code>height</code> of 66.'');'
|
||
|
|
- text: The fourth <code>rect</code> should have a <code>height</code> of 51.
|
||
|
|
testString: 'assert($(''rect'').eq(3).attr(''height'') == ''51'', ''The fourth <code>rect</code> should have a <code>height</code> of 51.'');'
|
||
|
|
- text: The fifth <code>rect</code> should have a <code>height</code> of 75.
|
||
|
|
testString: 'assert($(''rect'').eq(4).attr(''height'') == ''75'', ''The fifth <code>rect</code> should have a <code>height</code> of 75.'');'
|
||
|
|
- text: The sixth <code>rect</code> should have a <code>height</code> of 54.
|
||
|
|
testString: 'assert($(''rect'').eq(5).attr(''height'') == ''54'', ''The sixth <code>rect</code> should have a <code>height</code> of 54.'');'
|
||
|
|
- text: The seventh <code>rect</code> should have a <code>height</code> of 87.
|
||
|
|
testString: 'assert($(''rect'').eq(6).attr(''height'') == ''87'', ''The seventh <code>rect</code> should have a <code>height</code> of 87.'');'
|
||
|
|
- text: The eighth <code>rect</code> should have a <code>height</code> of 42.
|
||
|
|
testString: 'assert($(''rect'').eq(7).attr(''height'') == ''42'', ''The eighth <code>rect</code> should have a <code>height</code> of 42.'');'
|
||
|
|
- text: The ninth <code>rect</code> should have a <code>height</code> of 27.
|
||
|
|
testString: 'assert($(''rect'').eq(8).attr(''height'') == ''27'', ''The ninth <code>rect</code> should have a <code>height</code> of 27.'');'
|
||
|
|
|
||
|
|
```
|
||
|
|
|
||
|
|
</section>
|
||
|
|
|
||
|
|
## Challenge Seed
|
||
|
|
<section id='challengeSeed'>
|
||
|
|
|
||
|
|
<div id='html-seed'>
|
||
|
|
|
||
|
|
```html
|
||
|
|
<body>
|
||
|
|
<script>
|
||
|
|
const dataset = [12, 31, 22, 17, 25, 18, 29, 14, 9];
|
||
|
|
|
||
|
|
const w = 500;
|
||
|
|
const h = 100;
|
||
|
|
|
||
|
|
const svg = d3.select("body")
|
||
|
|
.append("svg")
|
||
|
|
.attr("width", w)
|
||
|
|
.attr("height", h);
|
||
|
|
|
||
|
|
svg.selectAll("rect")
|
||
|
|
.data(dataset)
|
||
|
|
.enter()
|
||
|
|
.append("rect")
|
||
|
|
.attr("x", (d, i) => i * 30)
|
||
|
|
.attr("y", 0)
|
||
|
|
.attr("width", 25)
|
||
|
|
.attr("height", (d, i) => {
|
||
|
|
// Add your code below this line
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
// Add your code above this line
|
||
|
|
});
|
||
|
|
</script>
|
||
|
|
</body>
|
||
|
|
```
|
||
|
|
|
||
|
|
</div>
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
</section>
|
||
|
|
|
||
|
|
## Solution
|
||
|
|
<section id='solution'>
|
||
|
|
|
||
|
|
```js
|
||
|
|
// solution required
|
||
|
|
```
|
||
|
|
</section>
|