音量表（VU Meter）
Highcharts 音量表（VU Meter）
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 | 布布教程(jiaocheng.bubufx.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>