225 lines
		
	
	
		
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			Markdown
		
	
	
	
	
	
		
		
			
		
	
	
			225 lines
		
	
	
		
			5.5 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
|   | --- | ||
|  | id: 587d7fab367417b2b2512bd9 | ||
|  | title: Add Labels to Scatter Plot Circles | ||
|  | challengeType: 6 | ||
|  | forumTopicId: 301477 | ||
|  | dashedName: add-labels-to-scatter-plot-circles | ||
|  | --- | ||
|  | 
 | ||
|  | # --description--
 | ||
|  | 
 | ||
|  | You can add text to create labels for the points in a scatter plot. | ||
|  | 
 | ||
|  | The goal is to display the comma-separated values for the first (`x`) and second (`y`) fields of each item in `dataset`. | ||
|  | 
 | ||
|  | The `text` nodes need `x` and `y` attributes to position it on the SVG canvas. In this challenge, the `y` value (which determines height) can use the same value that the `circle` uses for its `cy` attribute. The `x` value can be slightly larger than the `cx` value of the `circle`, so the label is visible. This will push the label to the right of the plotted point. | ||
|  | 
 | ||
|  | # --instructions--
 | ||
|  | 
 | ||
|  | Label each point on the scatter plot using the `text` elements. The text of the label should be the two values separated by a comma and a space. For example, the label for the first point is "34, 78". Set the `x` attribute so it's 5 units more than the value you used for the `cx` attribute on the `circle`. Set the `y` attribute the same way that's used for the `cy` value on the `circle`. | ||
|  | 
 | ||
|  | # --hints--
 | ||
|  | 
 | ||
|  | Your code should have 10 `text` elements. | ||
|  | 
 | ||
|  | ```js | ||
|  | assert($('text').length == 10); | ||
|  | ``` | ||
|  | 
 | ||
|  | The first label should have text of "34, 78", an `x` value of 39, and a `y` value of 422. | ||
|  | 
 | ||
|  | ```js | ||
|  | assert( | ||
|  |   $('text').eq(0).text() == '34, 78' && | ||
|  |     $('text').eq(0).attr('x') == '39' && | ||
|  |     $('text').eq(0).attr('y') == '422' | ||
|  | ); | ||
|  | ``` | ||
|  | 
 | ||
|  | The second label should have text of "109, 280", an `x` value of 114, and a `y` value of 220. | ||
|  | 
 | ||
|  | ```js | ||
|  | assert( | ||
|  |   $('text').eq(1).text() == '109, 280' && | ||
|  |     $('text').eq(1).attr('x') == '114' && | ||
|  |     $('text').eq(1).attr('y') == '220' | ||
|  | ); | ||
|  | ``` | ||
|  | 
 | ||
|  | The third label should have text of "310, 120", an `x` value of 315, and a `y` value of 380. | ||
|  | 
 | ||
|  | ```js | ||
|  | assert( | ||
|  |   $('text').eq(2).text() == '310, 120' && | ||
|  |     $('text').eq(2).attr('x') == '315' && | ||
|  |     $('text').eq(2).attr('y') == '380' | ||
|  | ); | ||
|  | ``` | ||
|  | 
 | ||
|  | The fourth label should have text of "79, 411", an `x` value of 84, and a `y` value of 89. | ||
|  | 
 | ||
|  | ```js | ||
|  | assert( | ||
|  |   $('text').eq(3).text() == '79, 411' && | ||
|  |     $('text').eq(3).attr('x') == '84' && | ||
|  |     $('text').eq(3).attr('y') == '89' | ||
|  | ); | ||
|  | ``` | ||
|  | 
 | ||
|  | The fifth label should have text of "420, 220", an `x` value of 425, and a `y` value of 280. | ||
|  | 
 | ||
|  | ```js | ||
|  | assert( | ||
|  |   $('text').eq(4).text() == '420, 220' && | ||
|  |     $('text').eq(4).attr('x') == '425' && | ||
|  |     $('text').eq(4).attr('y') == '280' | ||
|  | ); | ||
|  | ``` | ||
|  | 
 | ||
|  | The sixth label should have text of "233, 145", an `x` value of 238, and a `y` value of 355. | ||
|  | 
 | ||
|  | ```js | ||
|  | assert( | ||
|  |   $('text').eq(5).text() == '233, 145' && | ||
|  |     $('text').eq(5).attr('x') == '238' && | ||
|  |     $('text').eq(5).attr('y') == '355' | ||
|  | ); | ||
|  | ``` | ||
|  | 
 | ||
|  | The seventh label should have text of "333, 96", an `x` value of 338, and a `y` value of 404. | ||
|  | 
 | ||
|  | ```js | ||
|  | assert( | ||
|  |   $('text').eq(6).text() == '333, 96' && | ||
|  |     $('text').eq(6).attr('x') == '338' && | ||
|  |     $('text').eq(6).attr('y') == '404' | ||
|  | ); | ||
|  | ``` | ||
|  | 
 | ||
|  | The eighth label should have text of "222, 333", an `x` value of 227, and a `y` value of 167. | ||
|  | 
 | ||
|  | ```js | ||
|  | assert( | ||
|  |   $('text').eq(7).text() == '222, 333' && | ||
|  |     $('text').eq(7).attr('x') == '227' && | ||
|  |     $('text').eq(7).attr('y') == '167' | ||
|  | ); | ||
|  | ``` | ||
|  | 
 | ||
|  | The ninth label should have text of "78, 320", an `x` value of 83, and a `y` value of 180. | ||
|  | 
 | ||
|  | ```js | ||
|  | assert( | ||
|  |   $('text').eq(8).text() == '78, 320' && | ||
|  |     $('text').eq(8).attr('x') == '83' && | ||
|  |     $('text').eq(8).attr('y') == '180' | ||
|  | ); | ||
|  | ``` | ||
|  | 
 | ||
|  | The tenth label should have text of "21, 123", an `x` value of 26, and a `y` value of 377. | ||
|  | 
 | ||
|  | ```js | ||
|  | assert( | ||
|  |   $('text').eq(9).text() == '21, 123' && | ||
|  |     $('text').eq(9).attr('x') == '26' && | ||
|  |     $('text').eq(9).attr('y') == '377' | ||
|  | ); | ||
|  | ``` | ||
|  | 
 | ||
|  | # --seed--
 | ||
|  | 
 | ||
|  | ## --seed-contents--
 | ||
|  | 
 | ||
|  | ```html | ||
|  | <body> | ||
|  |   <script> | ||
|  |     const dataset = [ | ||
|  |                   [ 34,    78 ], | ||
|  |                   [ 109,   280 ], | ||
|  |                   [ 310,   120 ], | ||
|  |                   [ 79,    411 ], | ||
|  |                   [ 420,   220 ], | ||
|  |                   [ 233,   145 ], | ||
|  |                   [ 333,   96 ], | ||
|  |                   [ 222,   333 ], | ||
|  |                   [ 78,    320 ], | ||
|  |                   [ 21,    123 ] | ||
|  |                 ]; | ||
|  | 
 | ||
|  | 
 | ||
|  |     const w = 500; | ||
|  |     const h = 500; | ||
|  | 
 | ||
|  |     const svg = d3.select("body") | ||
|  |                   .append("svg") | ||
|  |                   .attr("width", w) | ||
|  |                   .attr("height", h); | ||
|  | 
 | ||
|  |     svg.selectAll("circle") | ||
|  |        .data(dataset) | ||
|  |        .enter() | ||
|  |        .append("circle") | ||
|  |        .attr("cx", (d, i) => d[0]) | ||
|  |        .attr("cy", (d, i) => h - d[1]) | ||
|  |        .attr("r", 5); | ||
|  | 
 | ||
|  |     svg.selectAll("text") | ||
|  |        .data(dataset) | ||
|  |        .enter() | ||
|  |        .append("text") | ||
|  |        // Add your code below this line | ||
|  | 
 | ||
|  | 
 | ||
|  | 
 | ||
|  |        // Add your code above this line | ||
|  |   </script> | ||
|  | </body> | ||
|  | ``` | ||
|  | 
 | ||
|  | # --solutions--
 | ||
|  | 
 | ||
|  | ```html | ||
|  | <body> | ||
|  |   <script> | ||
|  |     const dataset = [ | ||
|  |                   [ 34,    78 ], | ||
|  |                   [ 109,   280 ], | ||
|  |                   [ 310,   120 ], | ||
|  |                   [ 79,    411 ], | ||
|  |                   [ 420,   220 ], | ||
|  |                   [ 233,   145 ], | ||
|  |                   [ 333,   96 ], | ||
|  |                   [ 222,   333 ], | ||
|  |                   [ 78,    320 ], | ||
|  |                   [ 21,    123 ] | ||
|  |                 ]; | ||
|  | 
 | ||
|  | 
 | ||
|  |     const w = 500; | ||
|  |     const h = 500; | ||
|  | 
 | ||
|  |     const svg = d3.select("body") | ||
|  |                   .append("svg") | ||
|  |                   .attr("width", w) | ||
|  |                   .attr("height", h); | ||
|  | 
 | ||
|  |     svg.selectAll("circle") | ||
|  |        .data(dataset) | ||
|  |        .enter() | ||
|  |        .append("circle") | ||
|  |        .attr("cx", (d, i) => d[0]) | ||
|  |        .attr("cy", (d, i) => h - d[1]) | ||
|  |        .attr("r", 5); | ||
|  | 
 | ||
|  |     svg.selectAll("text") | ||
|  |        .data(dataset) | ||
|  |        .enter() | ||
|  |        .append("text") | ||
|  |        .attr("x", (d) => d[0] + 5) | ||
|  |        .attr("y", (d) => h - d[1]) | ||
|  |        .text((d) => (d[0] + ", " + d[1])) | ||
|  | 
 | ||
|  |   </script> | ||
|  | </body> | ||
|  | ``` |