Chart.js
Chart.js是一个免费的JavaScript图表库，用于创建基于HTML的图表。它是最简单的JavaScript可视化库之一，并内置了多种图表类型:
- 散点图
- 折线图
- 条形图
- 饼图
- 圆环图
- 气泡图
- 面积图
- 雷达图
- 混合图表
如何使用 Chart.js?
1. 添加指向提供内容分发网络 (CDN) 的链接:
<script
src="https://cdn.jsdelivr.net/npm/chart.js@4.5.0">
</script>2.在HTML中你想绘制图表的位置添加一个<canvas> 标签:
<canvas>
id="myChart" style="width:100%;max-width:700px"
</canvas>
canvas元素必须具有唯一的id。
典型柱状图语法:
const myChart = new Chart("myChart", {
type: "bar",
data: {},
options: {}
});
典型折线图语法:
const myChart = new Chart("myChart", {
type: "line",
data: {},
options: {}
});柱状图
源代码
const xValues = ["Italy", "France", "Spain", "USA", "Argentina"];
const yValues = [55, 49, 44, 24, 15];
const barColors = ["red", "green","blue","orange","brown"];
new Chart("myChart", {
type: "bar",
data: {
labels: xValues,
datasets: [{
backgroundColor: barColors,
data: yValues
}]
},
options: {...}
});
颜色色调:
const barColors = [
"rgba(0,0,255,1.0)",
"rgba(0,0,255,0.8)",
"rgba(0,0,255,0.6)",
"rgba(0,0,255,0.4)",
"rgba(0,0,255,0.2)",
];
饼图
示例
new Chart("myChart", {
type: "pie",
data: {
labels: xValues,
datasets: [{
backgroundColor: barColors,
data: yValues
}]
},
options: {
title: {
display: true,
text: "World Wide Wine Production"
}
}
});
甜甜圈图表
散点图
房价与房屋面积
源代码
const xyValues = [
{x:50, y:7},
{x:60, y:8},
{x:70, y:8},
{x:80, y:9},
{x:90, y:9},
{x:100, y:9},
{x:110, y:10},
{x:120, y:11},
{x:130, y:14},
{x:140, y:14},
{x:150, y:15}
];
new Chart("myChart", {
type: "scatter",
data: {
datasets: [{
pointRadius: 4,
pointBackgroundColor: "rgba(0,0,255,1)",
data: xyValues
}]
},
options:{...}
});
折线图
房价与房屋面积
源代码
const xValues = [50,60,70,80,90,100,110,120,130,140,150];
const yValues = [7,8,8,9,9,9,10,11,14,14,15];
new Chart("myChart", {
type: "line",
data: {
labels: xValues,
datasets: [{
backgroundColor:"rgba(0,0,255,1.0)",
borderColor: "rgba(0,0,255,0.1)",
data: yValues
}]
},
options:{...}
});
如果将边框颜色设置为零，则可以绘制散点图折线图:
borderColor: "rgba(0,0,0,0)",
多行
源代码
const xValues = [100,200,300,400,500,600,700,800,900,1000];
new Chart("myChart", {
type: "line",
data: {
labels: xValues,
datasets: [{
data: [860,1140,1060,1060,1070,1110,1330,2210,7830,2478],
borderColor: "red",
fill: false
},{
data: [1600,1700,1700,1900,2000,2700,4000,5000,6000,7000],
borderColor: "green",
fill: false
},{
data: [300,700,2000,5000,6000,4000,2000,1000,200,100],
borderColor: "blue",
fill: false
}]
},
options: {
legend: {display: false}
}
});
线性图
源代码
const xValues = [];
const yValues = [];
generateData("x * 2 + 7", 0, 10, 0.5);
const ctx = document.getElementById('myChart');
new Chart(ctx, {
type: "line",
data: {
labels: xValues,
datasets: [{
fill: false,
pointRadius: 1,
borderColor: "rgba(255,0,0,0.5)",
data: yValues
}]
},
options: {...}
});
function generateData(value, i1, i2, step = 1) {
for (let x = i1; x<= i2; x += step) {
yValues.push(eval(value));
xValues.push(x);
}
}
