d3.js-demo/testD3_chp9_1.html

<!DOCTYPE html>
<html>
  <head>
    <title>testD3_chp9_1.html</title>
	
	<script type="text/javascript" src="http://d3js.org/d3.v5.min.js">
	</script>
	
    <meta name="keywords" content="keyword1,keyword2,keyword3">
    <meta name="description" content="this is my page">
    <meta name="content-type" content="text/html; charset=UTF-8">
    
    <!--<link rel="stylesheet" type="text/css" href="./styles.css">-->

  </head>
  
  <body>
    <svg width="960" height="600"></svg>
    <script>
    	var marge = {top:60,bottom:60,left:60,right:60}
    	var svg = d3.select("svg");//得到SVG画布
    	var width = svg.attr("width");//得到画布的宽
    	var height = svg.attr("height");//得到画布的长
    	var g = svg.append("g")
    		.attr("transform","translate("+marge.top+","+marge.left+")");
    	
    	var dataset = [10,20,30,23,13,40,27,35,20];
   
    	var xScale = d3.scaleBand()
    		.domain(d3.range(dataset.length))
    		.rangeRound([0,width-marge.left-marge.right]);
    	var xAxis = d3.axisBottom(xScale);
    		
    	var yScale = d3.scaleLinear()
    		.domain([0,d3.max(dataset)])
    		.range([height-marge.top-marge.bottom,0]);
    	var yAxis = d3.axisLeft(yScale);
    	
    	g.append("g")
    		.attr("transform","translate("+0+","+(height-marge.top-marge.bottom)+")")
    		.call(xAxis);
    	g.append("g")
    		.attr("transform","translate(0,0)")
    		.call(yAxis);
    		
    	//绘制矩形和文字
    	var gs = g.selectAll(".rect")
    		.data(dataset)
    		.enter()
    		.append("g");
    	
    	//绘制矩形
    	var rectPadding = 20;//矩形之间的间隙
    	gs.append("rect")
    		.attr("x",function(d,i){
    			return xScale(i)+rectPadding/2;
    		})	
    		.attr("y",function(d){
    			return yScale(d);
    		})
    		.attr("width",function(){
    			return xScale.step()-rectPadding;
    		})
    		.attr("height",function(d){
    			return height-marge.top-marge.bottom-yScale(d);
    		})
    		.attr("fill","blue");
    	//绘制文字
    	gs.append("text")
    		.attr("x",function(d,i){
    			return xScale(i)+rectPadding/2;
    		})
    		.attr("y",function(d){
            return yScale(d);
        	})
        	.attr("dx",function(){
        		(xScale.step()-rectPadding)/2;
        	})
        	.attr("dy",20)
        	.text(function(d){
        		return d;
        	})
    </script>
  </body>
</html>