根据选择输入更改 d3 中的数据答案

【问题标题】：Changing Data in d3 Based on Selection Input根据选择输入更改 d3 中的数据
【发布时间】：2016-10-29 00:15:40
【问题描述】：

我目前正在使用 d3.js 和 HTML 构建图表。我正在尝试通过添加一个选择器来输入交互性，该选择器会根据您的选择更改显示的数据。我完全不确定如何让选择器更改正在使用的数据。

<!DOCTYPE html>
<html>
<head>
	<meta><meta http-equiv="refresh" content="90">
    <meta name="description" content="Drawing Shapes w/ D3 - " />
    <meta charset="utf-8">
	<title>Resources per Project</title>
	<script src="http://d3js.org/d3.v3.min.js" charset="utf-8"></script>

	<style type="text/css">
	h1 {
		font-size: 35px;
		color: darkgrey;
		font-family: Helvetica;
		border-bottom-width: 3px;
		border-bottom-style: dashed;
		border-bottom-color: black;
	}
	h2 {
		font-size: 20px;
		color: black;
		font-family: Helvetica;
		text-decoration: underline;
		margin-left: 290px;
		margin-top: 2px;
	}
	</style>
</head>
<body>
<h1>Resources used per Project</h1>

<p>Choose Month:
	<select id="label-option">
		<option value="April">April</option>
		<option value="May">May</option>
		<option value="June">June</option>
		<option value="July">July</option>
		<option value="August">August</option>
		<option value="September">September</option>
	</select>
<script type="text/javascript">
	var width = 800
	var height = 500
	var emptyVar = 0
	var dataArrayProjects = ['2G','An','At','Au','AW','Ch','CI','CN']
	var April = [0.35,1.66,3.04,1.54,3.45,2.56,2.29,1.37]
	var May = [0.36,1.69,3.08,1.54,3.62,2.61,2.22,1.44]
	var June = [0.34,1.7,3.08,1.63,3.66,2.68,2.24,1.51]
	var July = [0.3,1.72,3.17,1.67,3.56,2.56,2.17,1.44]
	var August = [0.28,1.79,3.18,1.71,3.62,2.73,2.26,1.54]
	var September = [0.23,1.74,3.12,1.61,3.66,2.71,2.2,1.48]

	var widthScale = d3.scale.linear()
					.domain([0, 4])
					.range([0, width-60]);

	var heightScale = d3.scale.ordinal()
	    .domain(dataArrayProjects)
	    .rangePoints([10, height-85]);

	var color = d3.scale.linear()
				.domain([0,4])
				.range(["#000066", "#22abff"])

	var axis = d3.svg.axis()
				.ticks("10")
				.scale(widthScale);

	var yAxis = d3.svg.axis()
	    .scale(heightScale)
	    .orient("left");

	var canvas = d3.select("body")
				.append("svg")
				.attr("width", width)
				.attr("height", height)
				.append("g")
				.attr("transform", "translate(40, 0)");

	var bars = canvas.selectAll("rect")
				.data(April)
				.enter()
					.append("rect")
						.attr("width", emptyVar)
						.attr("height", 50)
						.attr("fill", function(d) { return color(d) })
						.attr("y", function(d, i) { return i * 55 })

	canvas.append("g")
		.attr("transform", "translate(0, 430)")
		.attr("font-family", "Helvetica")
		.attr("font-size", "15px")
		.call(axis);

	canvas.append("g")
			.attr("font-family", "Helvetica")
			.attr("font-size", "15px")
			.style("fill", "black")
		    .attr("class", "y axis")
		    .call(yAxis);

	bars.transition()
			.duration(1500)
			.delay(200)
			.attr("width", function(d) { return widthScale(d); })


</script>
<h2>Resources</h2>
</body>
</html>

所以您知道变量 April、May、June、July、August 和 September 是我希望在它们之间进行更改的变量，并且“bars”变量中的 .data 选择器是数据应该在月份之间更改的位置。

提前致谢！

【问题讨论】：

标签： javascript html d3.js graph visualization

【解决方案1】：

您可以将侦听器附加到选择中，该侦听器将在选择更改时收到通知。

  d3.select("#label-option").on("change", change);//attache listener
  //on change update bars.
  function change() {
    var data = April;
    if (this.selectedIndex == 1){
      data = May;//return may Data
    } else if (this.selectedIndex == 2){
      data = June;//return June Data
    } else if (this.selectedIndex == 3){
      data = July;
    } else if (this.selectedIndex == 4){
      data = August;
    } else if (this.selectedIndex == 5){
      data = September;
    }
    //select all bars and set the new data
    canvas.selectAll("rect")
    .data(data)
    .attr("width", emptyVar)
    .attr("height", 50)
    .attr("fill", function(d) {
      return color(d)
    })
    .attr("y", function(d, i) {
      return i * 55
    })
   bars.transition()
    .duration(1500)
    .delay(200)
    .attr("width", function(d) {
      return widthScale(d);//transition to new width
    })        
  }

工作代码here

【讨论】：