日期:2014-05-16 浏览次数:20338 次
一、使用随机数值填充每一条
1、建立新的空的数据集数组
var dataset = []; //Initialize empty array
2、循环25次产生新的值
for (var i = 0; i < 25; i++) { //Loop 25 times
3、产生0-30的随机数
var newNumber = Math.random() * 30; //New random number (0-30)
4、将数据加入数据集数组
dataset.push(newNumber); //Add new number to array
}
5、还可以产生整数
var newNumber = Math.round(Math.random() * 30);
二、源码
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>testD3-5-dataPower.html</title> <script type="text/javascript" src="http://localhost:8080/spring/js/d3.v3.js"></script> <style type="text/css"> div.bar { display: inline-block; width: 20px; height: 75px; /* Gets overriden by D3-assigned height below */ margin-right: 2px; background-color: teal; } </style> </head> <body> <script type="text/javascript"> var dataset = []; //Initialize empty array for (var i = 0; i < 25; i++) { //Loop 25 times var newNumber = Math.round(Math.random() * 30); //New random integer (0-30) dataset = dataset.concat(newNumber); //Add new number to array } d3.select("body").selectAll("div") .data(dataset) .enter() .append("div") .attr("class", "bar") .style("height", function(d) { var barHeight = d * 5; return barHeight + "px"; }); </script> </body> </html>
三、效果