概览
在许多 Google 图表中，数据值都显示在精确的点。折线图就是由线条连接的这些点的集合，而散点图只不过是多个点。
在除散点图之外的所有图表中，这些点的大小默认为零。您可以使用 pointSize 选项控制其大小，使用 pointShape 选项控制其形状。
在上方，您可以看到一个包含 6 个系列的图表，每个系列的 pointSize 为 30，但 pointShape 各不相同。
var options = {
legend: 'none',
hAxis: { minValue: 0, maxValue: 7 },
pointSize: 30,
series: {
0: { pointShape: 'circle' },
1: { pointShape: 'triangle' },
2: { pointShape: 'square' },
3: { pointShape: 'diamond' },
4: { pointShape: 'star' },
5: { pointShape: 'polygon' }
}
};
<head>
<script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>
<script type="text/javascript">
google.charts.load("current", {packages:["corechart"]});
google.charts.setOnLoadCallback(drawChart);
function drawChart() {
var data = google.visualization.arrayToDataTable
([['X', '1', '2', '3', '4', '5', '6'],
[1, 2, null, null, null, null, null],
[2, null, 3, null, null, null, null],
[3, null, null, 4, null, null, null],
[4, null, null, null, 5, null, null],
[5, null, null, null, null, 6, null],
[6, null, null, null, null, null, 7]
]);
var options = {
legend: 'none',
pointSize: 30,
series: {
0: { pointShape: 'circle' },
1: { pointShape: 'triangle' },
2: { pointShape: 'square' },
3: { pointShape: 'diamond' },
4: { pointShape: 'star' },
5: { pointShape: 'polygon' }
}
};
var chart = new google.visualization.LineChart(document.getElementById('chart_div'));
chart.draw(data, options);
}
</script>
</head>
<body>
<div id="chart_div" style="width: 900px; height: 500px;"></div>
</body>
</html>
一些简单示例
与上一部分中的图表不同，大多数图表只有一个系列。下面是一个包含 20 点圆形点的折线图表示例：
由于默认的 pointShape 是圆形，因此我们可以在选项中不添加它：
var options = {
legend: 'none',
hAxis: { minValue: 0, maxValue: 9 },
curveType: 'function',
pointSize: 20,
};
<head>
<script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>
<script type="text/javascript">
google.charts.load("current", {packages:["corechart"]});
google.charts.setOnLoadCallback(drawChart);
function drawChart() {
var data = google.visualization.arrayToDataTable
([['X', 'Y'],
[1, 3],
[2, 2.5],
[3, 3],
[4, 4],
[5, 4],
[6, 3],
[7, 2.5],
[8, 3]
]);
var options = {
legend: 'none',
hAxis: { minValue: 0, maxValue: 9 },
curveType: 'function',
pointSize: 20,
};
var chart = new google.visualization.LineChart(document.getElementById('chart_div'));
chart.draw(data, options);
}
</script>
</head>
<body>
<div id="chart_div" style="width: 900px; height: 500px;"></div>
</body>
</html>
您可以将 pointShape 设置为“三角形”“方形”“菱形”“星形”或“多边形”，从而将其从“圆形”更改为其他形状：
var options = {
legend: 'none',
hAxis: { minValue: 0, maxValue: 9 },
colors: ['#795548'],
pointSize: 20,
pointShape: 'square'
};
<head>
<script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>
<script type="text/javascript">
google.charts.load("current", {packages:["corechart"]});
google.charts.setOnLoadCallback(drawChart);
function drawChart() {
var data = google.visualization.arrayToDataTable
([['X', 'Y'],
[1, 3],
[2, 2.5],
[3, 3],
[4, 4],
[5, 4],
[6, 3],
[7, 2.5],
[8, 3]
]);
var options = {
legend: 'none',
hAxis: { minValue: 0, maxValue: 9 },
colors: ['#795548'],
pointSize: 20,
pointShape: 'square'
};
var chart = new google.visualization.LineChart(document.getElementById('chart_div'));
chart.draw(data, options);
}
</script>
</head>
<body>
<div id="chart_div" style="width: 900px; height: 500px;"></div>
</body>
</html>
“星形”和“多边形”形状可让您自定义边数，均默认设为 5。下面是一些四面星形：
var options = {
legend: 'none',
hAxis: { minValue: 0, maxValue: 9 },
colors: ['#EF851C'],
pointSize: 30,
pointShape: { type: 'star', sides: 4 }
};
<html>
<head>
<script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>
<script type="text/javascript">
google.charts.load("current", {packages:["corechart"]});
google.charts.setOnLoadCallback(drawChart);
function drawChart() {
var data = google.visualization.arrayToDataTable
([['X', 'Y'],
[1, 3],
[2, 2.5],
[3, 3],
[4, 4],
[5, 4],
[6, 3],
[7, 2.5],
[8, 3]
]);
var options = {
legend: 'none',
hAxis: { minValue: 0, maxValue: 9 },
colors: ['#EF851C'],
pointSize: 30,
pointShape: { type: 'star', sides: 4 }
};
var chart = new google.visualization.LineChart(document.getElementById('chart_div'));
chart.draw(data, options);
}
</script>
</head>
<body>
<div id="chart_div" style="width: 900px; height: 500px;"></div>
</body>
</html>
可以使用 dent 选项进一步自定义星形，该选项用于控制星形的凹度。当凹陷接近零时，星体会呈海星状；当凹陷接近 1 时，它会膨胀超过等边多边形。
以下是五面星形的凹陷，范围为 0.05 至 0.8：
var options = {
legend: 'none',
hAxis: { textPosition: 'none' },
vAxis: { textPosition: 'none', gridlines: { count: 0 },
baselineColor: 'white' },
colors: ['#E94D20', '#ECA403', '#63A74A',
'#15A0C8', '#4151A3', '#703593', '#981B48'],
pointSize: 20,
annotations: { stemColor: 'white', textStyle: { fontSize: 16 } },
series: {
0: { pointShape: { type: 'star', sides: 5, dent: 0.05 } },
1: { pointShape: { type: 'star', sides: 5, dent: 0.1 } },
2: { pointShape: { type: 'star', sides: 5, dent: 0.2 } },
3: { pointShape: { type: 'star', sides: 5 } },
4: { pointShape: { type: 'star', sides: 5, dent: 0.5 } },
5: { pointShape: { type: 'star', sides: 5, dent: 0.7 } },
6: { pointShape: { type: 'star', sides: 5, dent: 0.8 } },
}
};
<html>
<head>
<script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>
<script type="text/javascript">
google.charts.load("current", {packages:["corechart"]});
google.charts.setOnLoadCallback(drawChart);
function drawChart() {
var data = new google.visualization.DataTable();
data.addColumn('string', 'Element');
data.addColumn('number', 'A');
data.addColumn( { type: 'string', role: 'annotation' });
data.addColumn('number', 'B');
data.addColumn( { type: 'string', role: 'annotation' });
data.addColumn('number', 'C');
data.addColumn( { type: 'string', role: 'annotation' });
data.addColumn('number', 'D');
data.addColumn( { type: 'string', role: 'annotation' });
data.addColumn('number', 'E');
data.addColumn( { type: 'string', role: 'annotation' });
data.addColumn('number', 'F');
data.addColumn( { type: 'string', role: 'annotation' });
data.addColumn('number', 'G');
data.addColumn( { type: 'string', role: 'annotation' });
data.addRow(['A', 1, "dent: 0.05", , , , , , , , , , , , null]);
data.addRow(['B', , , 1, "dent: 0.1", , , , , , , , , , null]);
data.addRow(['C', , , , , 1, "dent: 0.2", , , , , , , , null]);
data.addRow(['D', , , , , , , 1, "default", , , , , , null]);
data.addRow(['E', , , , , , , , , 1, "dent: 0.5", , , , null]);
data.addRow(['F', , , , , , , , , , , 1, "dent: 0.7", , null]);
data.addRow(['G', , , , , , , , , , , , , 1, "dent: 0.8"]);
var options = {
legend: 'none',
hAxis: { textPosition: 'none' },
vAxis: { textPosition: 'none', gridlines: { count: 0 },
baselineColor: 'white' },
colors: ['#E94D20', '#ECA403', '#63A74A',
'#15A0C8', '#4151A3', '#703593', '#981B48'],
pointSize: 20,
annotations: { stemColor: 'white', textStyle: { fontSize: 16 } },
series: {
0: { pointShape: { type: 'star', sides: 5, dent: 0.05 } },
1: { pointShape: { type: 'star', sides: 5, dent: 0.1 } },
2: { pointShape: { type: 'star', sides: 5, dent: 0.2 } },
3: { pointShape: { type: 'star', sides: 5 } },
4: { pointShape: { type: 'star', sides: 5, dent: 0.5 } },
5: { pointShape: { type: 'star', sides: 5, dent: 0.7 } },
6: { pointShape: { type: 'star', sides: 5, dent: 0.8 } },
}
};
var chart = new google.visualization.LineChart(document.getElementById('chart_div'));
chart.draw(data, options);
}
</script>
</head>
<body>
<div id="chart_div" style="width: 900px; height: 500px;"></div>
</body>
</html>
旋转
所有的点形状均可通过 rotation 选项进行旋转（以度为单位）。例如，我们可以将三角形旋转 180 度，让这些三角形在以下面积图中向下指：
var options = {
legend: 'none',
colors: ['#15A0C8'],
pointSize: 30,
pointShape: { type: 'triangle', rotation: 180 }
};
<head>
<script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>
<script type="text/javascript">
google.charts.load("current", {packages:["corechart"]});
google.charts.setOnLoadCallback(drawChart);
function drawChart() {
var data = google.visualization.arrayToDataTable
([['X', 'Y'],
[1, 3],
[2, 2.5],
[3, 2],
[4, 3],
[5, 4.5],
[6, 6.5],
[7, 9],
[8, 12]
]);
var options = {
legend: 'none',
colors: ['#15A0C8'],
pointSize: 30,
pointShape: { type: 'triangle', rotation: 180 }
};
var chart = new google.visualization.AreaChart(document.getElementById('chart_div'));
chart.draw(data, options);
}
</script>
</head>
<body>
<div id="chart_div" style="width: 900px; height: 500px;"></div>
</body>
</html>
自定义单个点
默认情况下，应用于点的样式会应用于系列中的所有点。如果您想更改特定数据点的外观，可以通过设置样式来实现。
在下图中，我们增大了其中一个点的大小，将不透明度降低至 0.3，然后更改形状和颜色：
<html>
<head>
<script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>
<script type="text/javascript">
google.charts.load('current', {'packages':['corechart']});
google.charts.setOnLoadCallback(drawChart);
function drawChart() {
var data = google.visualization.arrayToDataTable
([['X', 'Y', {'type': 'string', 'role': 'style'}],
[1, 3, null],
[2, 2.5, null],
[3, 3, null],
[4, 4, null],
[5, 4, null],
[6, 3, 'point { size: 18; shape-type: star; fill-color: #a52714; }'],
[7, 2.5, null],
[8, 3, null]
]);
var options = {
legend: 'none',
hAxis: { minValue: 0, maxValue: 9 },
curveType: 'function',
pointSize: 7,
dataOpacity: 0.3
};
var chart = new google.visualization.LineChart(document.getElementById('chart_div'));
chart.draw(data, options);
}
</script>
</head>
<body>
<div id="chart_div" style="width: 900px; height: 500px;"></div>
</body>
</html>
可以进行以下样式自定义：
fill-color（以十六进制字符串形式指定。）shape-dentshape-rotationshape-sidesshape-typestroke-color（以十六进制字符串形式指定。）stroke-width（以十六进制字符串形式指定。）sizevisible（点是否可见。）
不透明度并非通过样式控制，而是通过 dataOpacity 选项控制。