图表如何支持自适应宽度

(1) 方式一

var chart = new G2.Chart({
  id: 'c1',
  forceFit: true,
  height : 400
});

(2) 方式二

chart.forceFit();

如何格式化坐标轴文本

chart.axis('dim', {
  formatter: function(val) {
      return val + 'k';
  }
});

在线试一试

怎么控制坐标轴刻度线个数以及刻度线的间距

列定义中为对应的数据字段设置 tickCount 用于控制刻度线的个数;

chart.source(data, {
  y: {
    tickCount: 8
  }
});
// 或者使用 chart.col()
chart.col('y', {
  tickCount: 8
});

列定义中为对应的数据字段设置 tickInterval 用于控制刻度线的间距;

chart.source(data, {
  y: {
    tickInterval: 1000, // 当为时间类型时,请传入单位为微秒的数据
  }
});
// 或者使用 chart.col()
chart.col('y', {
  tickInterval: 1000
});

注意 tickCount 和 tickInterval 不可以同时设置。

示例:

var data = [
  {"value":10,"time":"2015-03-01T00:00:00.000Z"},
  {"value":15,"time":"2015-03-02T00:00:00.000Z"},
  {"value":26,"time":"2015-03-03T00:00:00.000Z"},
  {"value":9,"time":"2015-03-04T00:00:00.000Z"},
  {"value":12,"time":"2015-03-05T00:00:00.000Z"},
  {"value":23,"time":"2015-03-06T00:00:00.000Z"},
  {"value":18,"time":"2015-03-07T00:00:00.000Z"},
  {"value":21,"time":"2015-03-08T00:00:00.000Z"},
  {"value":52,"time":"2015-03-09T00:00:00.000Z"},
  {"value":35,"time":"2015-03-10T00:00:00.000Z"},
  {"value":47,"time":"2015-03-11T00:00:00.000Z"},
  {"value":30,"time":"2015-03-12T00:00:00.000Z"},
  {"value":45,"time":"2015-03-13T00:00:00.000Z"},
  {"value":75,"time":"2015-03-14T00:00:00.000Z"},
  {"value":34,"time":"2015-03-15T00:00:00.000Z"},
];
var chart = new G2.Chart({
  id : 'chart1',
  forceFit: true,
  height : 334
});
var defs = {
  'time': {
    type: 'time',
    nice: false,
    mask: 'mm-dd',
    tickInterval: 2 * 24 * 60 * 60 * 1000 // 对于 linear 类型的数据,可以设置 tickInterval 参数来设定每个刻度之间的间距,time 类型的单位为微秒
  },
  value: {
    tickInterval: 10
  }
};
chart.source(data,defs);
chart.line().position('time*value').color('red');
chart.render();

如何控制坐标轴的显示的数值范围

列定义中,为对应的数据字段设置 minmax 字段。

chart.source(data, {
  y: {
    min: 0,
    max: 100
  }
});
// 或者使用 chart.col()
chart.col('y', {
  min: 0,
  max: 100
});

如何格式化图例的显示文本

在列定义中,为对应字段设置 formatter 函数。

chart.source(data, {
  y: {
    formatter: function(val) {
      if (val === 'male') {
        return '男';
      } else {
        return '女';
      }
    }
  }
});
// 或者使用 chart.col()
chart.col('y', {
  formatter: function(val) {
    if (val === 'male') {
      return '男';
    } else {
      return '女';
    }
  }
});

示例:

var data = [
  {genre: 'Sports', sold: 275},
  {genre: 'Strategy', sold: 115},
  {genre: 'Action', sold: 120},
  {genre: 'Shooter', sold: 350},
  {genre: 'Other', sold: 150},
];

var map = {
  'Sports': '运动',
  'Strategy': '策略',
  'Action': '动作类',
  'Shooter': '射击类',
  'Other': '其他'
};

var chart = new G2.Chart({
  id: 'chart2',  // 指定图表容器 ID
  height : 300,     // 指定图表高度
  forceFit: true,
});

chart.source(data, {
  genre: {
    formatter: function(val) {
      return map[val];
    }, // **关键代码**:在列定义中调用 formatter 回调函数,
    alias: '游戏种类' // 列定义,定义该属性显示的别名
  },
  sold: {
    alias: '销售量'
  }
});
chart.interval().position('genre*sold').color('genre');
chart.render();

如何设置图例项的初始状态

chart.filter('dim', arr)

可以过滤指定字段的数据,其中 arr 是一个数组,代表该 dim 字段你要保留的数据值。如果存在对应字段的图例,那么被过滤掉的类型会被取消选中,如下图表所示:

var data = [
  {"month":0,"tem":7,"city":"tokyo"},
  {"month":1,"tem":6.9,"city":"tokyo"},
  {"month":2,"tem":9.5,"city":"tokyo"},
  {"month":3,"tem":14.5,"city":"tokyo"},
  {"month":4,"tem":18.2,"city":"tokyo"},
  {"month":5,"tem":21.5,"city":"tokyo"},
  {"month":6,"tem":25.2,"city":"tokyo"},
  {"month":7,"tem":26.5,"city":"tokyo"},
  {"month":8,"tem":23.3,"city":"tokyo"},
  {"month":9,"tem":18.3,"city":"tokyo"},
  {"month":10,"tem":13.9,"city":"tokyo"},
  {"month":11,"tem":9.6,"city":"tokyo"},
  {"month":0,"tem":-0.2,"city":"newYork"},
  {"month":1,"tem":0.8,"city":"newYork"},
  {"month":2,"tem":5.7,"city":"newYork"},
  {"month":3,"tem":11.3,"city":"newYork"},
  {"month":4,"tem":17,"city":"newYork"},
  {"month":5,"tem":22,"city":"newYork"},
  {"month":6,"tem":24.8,"city":"newYork"},
  {"month":7,"tem":24.1,"city":"newYork"},
  {"month":8,"tem":20.1,"city":"newYork"},
  {"month":9,"tem":14.1,"city":"newYork"},
  {"month":10,"tem":8.6,"city":"newYork"},
  {"month":11,"tem":2.5,"city":"newYork"},
  {"month":0,"tem":-0.9,"city":"berlin"},
  {"month":1,"tem":0.6,"city":"berlin"},
  {"month":2,"tem":3.5,"city":"berlin"},
  {"month":3,"tem":8.4,"city":"berlin"},
  {"month":4,"tem":13.5,"city":"berlin"},
  {"month":5,"tem":17,"city":"berlin"},
  {"month":6,"tem":18.6,"city":"berlin"},
  {"month":7,"tem":17.9,"city":"berlin"},
  {"month":8,"tem":14.3,"city":"berlin"},
  {"month":9,"tem":9,"city":"berlin"},
  {"month":10,"tem":3.9,"city":"berlin"},
  {"month":11,"tem":1,"city":"berlin"}
];

var chart = new G2.Chart({
  id: 'c1',
  width: 800,
  height: 350
});

var defs = {'month':{
  type: 'cat',
  values: [
    '一月','二月','三月','四月','五月','六月',
    '七月','八月','九月','十月','十一月','十二月']
}};

chart.source(data,defs);

chart.filter('city', ['berlin']); // 只展示 berlin 的数据
chart.line().position('month*tem').color('city');
chart.render();

如何绘制多 y 轴图表

在 G2 中,实现多 Y 轴的绘制非常简单,用户完全不需要做任何配置。只要做到各个 geom 的 X 轴属性相同, Y 轴属性不同,G2 就会为您自动生成。

chart.interval().position('month*rainfall').color('#95ceff'); 
chart.line().position('month*temperature').color('#90ed7d').size(2).shape('smooth');

这个时候就会自动生成两条 y 轴,分别对应 rainfalltemperature

示例:

var data = [
  {"month":"Jan","rainfall":49.9,"seaLevelPressure":1016,"temperature":7},
  {"month":"Feb","rainfall":71.5,"seaLevelPressure":1016,"temperature":6.9},
  {"month":"Mar","rainfall":106.4,"seaLevelPressure":1015.9,"temperature":9.5},
  {"month":"Apr","rainfall":129.2,"seaLevelPressure":1015.5,"temperature":14.5},
  {"month":"May","rainfall":144,"seaLevelPressure":1012.3,"temperature":18.2},
  {"month":"Jun","rainfall":176,"seaLevelPressure":1009.5,"temperature":21.5},
  {"month":"Jul","rainfall":135.6,"seaLevelPressure":1009.6,"temperature":25.2},
  {"month":"Aug","rainfall":148.5,"seaLevelPressure":1010.2,"temperature":26.5},
  {"month":"Sep","rainfall":216.4,"seaLevelPressure":1013.1,"temperature":23.3},
  {"month":"Oct","rainfall":194.1,"seaLevelPressure":1016.9,"temperature":18.3},
  {"month":"Nov","rainfall":95.6,"seaLevelPressure":1018.2,"temperature":13.9},
  {"month":"Dec","rainfall":54.4,"seaLevelPressure":1016.7,"temperature":9.6}
];

var chart = new G2.Chart({
  id: 'chart3',
  forceFit: true, // 宽度自适应
  height: 300,
  plotCfg: {
    margin: [60, 160, 60, 90]
  }
});

chart.source(data, {
  rainfall: {
    min: 0,
    tickInterval: 50,
    alias: '降雨量'
  },
  temperature: {
    min: 5,
    tickInterval: 5,
    alias: '温度'
  },
  seaLevelPressure: {
    min: 1008,
    max: 1028,
    tickInterval: 4,
    alias: '海平面气压'
  }
});
// 左侧 Y 轴,即降雨量轴
chart.axis('rainfall', {
  formatter: function(val) {
    return val + ' mm'; // 格式化坐标轴显示
  },
  line: null,
  tickLine: null,
  titleOffset: 80,
  labels: {
    label: {
      fill: '#95ceff'
    }
  },
  title: {
    fill: '#95ceff',
    fontSize: 14
  }
});
// 右侧第一个 Y 轴,即温度轴
chart.axis('temperature', {
  formatter: function(val) {
    return val + ' °C'; // 格式化坐标轴显示
  },
  line: null,
  tickLine: null,
  titleOffset: 80,
  labels: {
    label: {
      fill: '#90ed7d'
    }
  },
  title: {
    fill: '#90ed7d',
    fontSize: 14
  }
});
// 右侧第二个 Y 轴,即海平面气压轴
chart.axis('seaLevelPressure', {
  formatter: function(val) {
    return val + ' mb'; // 格式化坐标轴显示
  },
  line: null,
  tickLine: null,
  titleOffset: 210,
  labelOffset: 80,
  labels: {
    label: {
      fill: '#333'
    }
  },
  title: {
    fill: '#333',
    fontSize: 14
  }
});

chart.axis('month', {title: null});
chart.legend({position: 'top'});
chart.tooltip({crosshairs: true});

chart.interval().position('month*rainfall').color('#95ceff'); // 降雨量
chart.line().position('month*temperature').color('#90ed7d').size(2).shape('smooth'); // 温度
chart.point().position('month*temperature').color('#90ed7d').shape('diamond');
chart.line().position('month*seaLevelPressure').shape('dotSmooth').size(2).color('#333'); // 海平面气压
chart.render();

如何绘制混合图表

G2 采用图层的设计,每一个几何标记 geom 对应一个图形,当需要绘制混合图表时,直接在 chart 对象上创建不同的 geom 几何对象即可。

image

在这个例子中除了生成多 Y 轴之外还绘制了混合图表(柱状图、线图以及点图)。

示例详见:如何绘制多 y 轴图表

如何修改 tooltip 的显示内容

G2 提供了多种修改 tooltip 显示内容的方法,详见 tooltip 提示信息 教程。

如何导出图片

直接调用 chart.downloadImage(); 即可导出图片。

但是注意最好在 chart 生成后延时几秒调用,因为 chart 默认是有执行动画的,如:

setTimeout(function() {
  chart.downloadImage();
}, 1500);