Highcharts 音量表（VU Meter）

Highcharts 测量图Highcharts 测量图

以下实例演示了音量表（VU Meter）。

我们在前面的章节已经了解了 Highcharts 基本配置语法。接下来让我们来看下其他的配置。

配置

chart.type 配置

配置 chart 的 type 为 'gauge' 。chart.type 描述了图表类型。默认值为 "line"。

var chart = {
   type: 'gauge'
};

pane 配置

pane 只适用在极坐标图和角度测量仪。此可配置对象持有组合x轴和y周的常规选项。每个x轴和y轴都可以通过索引关联到窗格中。

var pane = {
  startAngle: -150,  // x轴或测量轴的开始度数，以度数的方式给出。0是北
  endAngle: 150      //x轴极坐标或角度轴的最终度数，以度数的方式给出。0是北
};

实例

文件名：highcharts_vumeter.htm

<html>
<head>
<meta charset="UTF-8" />
<title>Highcharts 教程 | 码农教程(runcodex.com)</title>
<script src="http://apps.bdimg.com/libs/jquery/2.1.4/jquery.min.js"></script>
<script src="http://code.highcharts.com/highcharts.js"></script>
<script src="http://code.highcharts.com/highcharts-more.js"></script>   
</head>
<body>
<div id="container" style="width: 550px; height: 400px; margin: 0 auto"></div>
<script language="JavaScript">
$(document).ready(function() {  
   var chart = {      
      type: 'gauge',
      plotBorderWidth: 1,
      plotBackgroundColor: {
         linearGradient: { x1: 0, y1: 0, x2: 0, y2: 1 },
         stops: [
            [0, '#FFF4C6'],
            [0.3, '#FFFFFF'],
            [1, '#FFF4C6']
         ]
      },
      plotBackgroundImage: null,
      height: 200
   };
   var credits = {
      enabled: false
   };

   var title = {
      text: '音量表（VU Meter）'
   };

   var pane = [{
         startAngle: -45,
         endAngle: 45,
         background: null,
         center: ['25%', '145%'],
         size: 300
      }, {
         startAngle: -45,
         endAngle: 45,
         background: null,
         center: ['75%', '145%'],
         size: 300
   }];

   var yAxis = [{
         min: -20,
         max: 6,
         minorTickPosition: 'outside',
         tickPosition: 'outside',
         labels: {
            rotation: 'auto',
            distance: 20
         },
         plotBands: [{
            from: 0,
            to: 6,
            color: '#C02316',
            innerRadius: '100%',
            outerRadius: '105%'
         }],
         pane: 0,
         title: {
            text: 'VU<br/><span style="font-size:8px">Channel A</span>',
            y: -40
         }
      }, {
         min: -20,
         max: 6,
         minorTickPosition: 'outside',
         tickPosition: 'outside',
         labels: {
            rotation: 'auto',
            distance: 20
         },
         plotBands: [{
            from: 0,
            to: 6,
            color: '#C02316',
            innerRadius: '100%',
            outerRadius: '105%'
         }],
         pane: 1,
         title: {
            text: 'VU<br/><span style="font-size:8px">Channel B</span>',
            y: -40
         }
   }];
   
   var plotOptions = {
      gauge: {
            dataLabels: {
            enabled: false
         },
         dial: {
            radius: '100%'
         }
      }
   };
   var series= [{
        data: [-20],
        yAxis: 0
     }, {
        data: [-20],
        yAxis: 1
   }];     
      
   var json = {};   
   json.chart = chart; 
   json.credits = credits;
   json.title = title;       
   json.pane = pane; 
   json.yAxis = yAxis; 
   json.plotOptions = plotOptions;  
   json.series = series;      
   
   // Add some life
   var chartFunction = function (chart) {
      setInterval(function () {
         if (chart.series) { // the chart may be destroyed
            var left = chart.series[0].points[0],
            right = chart.series[1].points[0],
            leftVal,
            rightVal,
            inc = (Math.random() - 0.5) * 3;

            leftVal =  left.y + inc;
            rightVal = leftVal + inc / 3;
            if (leftVal < -20 || leftVal > 6) {
               leftVal = left.y - inc;
            }
            if (rightVal < -20 || rightVal > 6) {
               rightVal = leftVal;
            }

            left.update(leftVal, false);
            right.update(rightVal, false);
            chart.redraw();
         }
      }, 500);
   };
   
   $('#container').highcharts(json, chartFunction);  
});
</script>
</body>
</html>

以上实例输出结果为：

Highcharts 测量图Highcharts 测量图