在 Vega 中连接图表（行、列、网格）

Question

我想使用

group

标记在 Vega 中创建子可视化。下面您将找到一个最小的示例，其中第二个图与第一个图重叠，如标题中所示。

{
  "$schema": "https://vega.github.io/schema/vega/v5.json",
  "description": "A basic bar chart example, with value labels shown upon pointer hover.",
  "width": 400,
  "height": 200,
  "padding": 5,

  "data": [
    {
      "name": "table",
      "values": [
        {"category": "A", "amount": 28},
        {"category": "B", "amount": 55},
        {"category": "C", "amount": 43},
        {"category": "D", "amount": 91},
        {"category": "E", "amount": 81},
        {"category": "F", "amount": 53},
        {"category": "G", "amount": 19},
        {"category": "H", "amount": 87}
      ]
    }
  ],

  "scales": [
    {
      "name": "xscale",
      "type": "band",
      "domain": {"data": "table", "field": "category"},
      "range": "width",
      "padding": 0.05,
      "round": true
    },
    {
      "name": "yscale",
      "domain": {"data": "table", "field": "amount"},
      "nice": true,
      "range": "height"
    }
  ],

  "axes": [
    { "orient": "bottom", "scale": "xscale" },
    { "orient": "left", "scale": "yscale" }
  ],

  "marks": [
    {
      "type": "group",
      "name": "table1",
      "style": "cell",
      "title": {"text": "First Bar Plot", "frame": "group"},
      "encode": {
        "update": {
          "width": {"signal": "width"},
          "height": {"signal": "height"}
        }
      },
    "marks":[
    {
      "type": "rect",
      "from": {"data":"table"},
      "encode": {
        "enter": {
          "x": {"scale": "xscale", "field": "category"},
          "width": {"scale": "xscale", "band": 1},
          "y": {"scale": "yscale", "field": "amount"},
          "y2": {"scale": "yscale", "value": 0}
        },
        "update": {
          "fill": {"value": "steelblue"}
        },
        "hover": {
          "fill": {"value": "red"}
        }
      }
    },
    ]
    },

    {
      "type": "group",
      "name": "table2",
      "style": "cell",
      "title": {"text": "Second Bar Plot"},

      "encode": {
        "update": {
          "width": {"signal": "width"},
          "height": {"signal": "height"}
        }
      },

    "marks":[
    {
      "type": "rect",
      "from": {"data":"table"},
      "encode": {
        "enter": {
          "x": {"scale": "xscale", "field": "category"},
          "width": {"scale": "xscale", "band": 1},
          "y": {"scale": "yscale", "field": "amount"},
          "y2": {"scale": "yscale", "value": 0}
        },
        "update": {
          "fill": {"value": "steelblue"}
        },
        "hover": {
          "fill": {"value": "red"}
        }
      }
    },
    ]
    },
    
  ]
}

我本以为这两个地块是相邻的。此外，我想尝试将这些图放在一起，如果我正确理解文档，这似乎是可能的。

有人可以解释/告诉我吗：

1. 如何修改上面的代码，使两个条形图彼此相邻出现。

2. 如何修改上面的代码，使第二个条形图位于第一个条形图下方。

Answer 1

你需要一个布局。使用空布局：

{
  "$schema": "https://vega.github.io/schema/vega/v5.json",
  "description": "A basic bar chart example, with value labels shown upon pointer hover.",
  "width": 400,
  "height": 200,
  "padding": 5,
  "data": [
    {
      "name": "table",
      "values": [
        {"category": "A", "amount": 28},
        {"category": "B", "amount": 55},
        {"category": "C", "amount": 43},
        {"category": "D", "amount": 91},
        {"category": "E", "amount": 81},
        {"category": "F", "amount": 53},
        {"category": "G", "amount": 19},
        {"category": "H", "amount": 87}
      ]
    }
  ],
  "scales": [
    {
      "name": "xscale",
      "type": "band",
      "domain": {"data": "table", "field": "category"},
      "range": "width",
      "padding": 0.05,
      "round": true
    },
    {
      "name": "yscale",
      "domain": {"data": "table", "field": "amount"},
      "nice": true,
      "range": "height"
    }
  ],
  "axes": [
    {"orient": "bottom", "scale": "xscale"},
    {"orient": "left", "scale": "yscale"}
  ],
  "layout": {},
  "marks": [
    {
      "type": "group",
      "name": "table1",
      "style": "cell",
      "title": {"text": "First Bar Plot", "frame": "group"},
      "encode": {
        "update": {"width": {"signal": "width"}, "height": {"signal": "height"}}
      },
      "marks": [
        {
          "type": "rect",
          "from": {"data": "table"},
          "encode": {
            "enter": {
              "x": {"scale": "xscale", "field": "category"},
              "width": {"scale": "xscale", "band": 1},
              "y": {"scale": "yscale", "field": "amount"},
              "y2": {"scale": "yscale", "value": 0}
            },
            "update": {"fill": {"value": "steelblue"}},
            "hover": {"fill": {"value": "red"}}
          }
        }
      ]
    },
    {
      "type": "group",
      "name": "table2",
      "style": "cell",
      "title": {"text": "Second Bar Plot"},
      "encode": {
        "update": {"width": {"signal": "width"}, "height": {"signal": "height"}}
      },
      "marks": [
        {
          "type": "rect",
          "from": {"data": "table"},
          "encode": {
            "enter": {
              "x": {"scale": "xscale", "field": "category"},
              "width": {"scale": "xscale", "band": 1},
              "y": {"scale": "yscale", "field": "amount"},
              "y2": {"scale": "yscale", "value": 0}
            },
            "update": {"fill": {"value": "steelblue"}},
            "hover": {"fill": {"value": "red"}}
          }
        }
      ]
    }
  ]
}

具有列属性：

{
  "$schema": "https://vega.github.io/schema/vega/v5.json",
  "description": "A basic bar chart example, with value labels shown upon pointer hover.",
  "width": 400,
  "height": 200,
  "padding": 5,
  "data": [
    {
      "name": "table",
      "values": [
        {"category": "A", "amount": 28},
        {"category": "B", "amount": 55},
        {"category": "C", "amount": 43},
        {"category": "D", "amount": 91},
        {"category": "E", "amount": 81},
        {"category": "F", "amount": 53},
        {"category": "G", "amount": 19},
        {"category": "H", "amount": 87}
      ]
    }
  ],
  "scales": [
    {
      "name": "xscale",
      "type": "band",
      "domain": {"data": "table", "field": "category"},
      "range": "width",
      "padding": 0.05,
      "round": true
    },
    {
      "name": "yscale",
      "domain": {"data": "table", "field": "amount"},
      "nice": true,
      "range": "height"
    }
  ],
  "axes": [
    {"orient": "bottom", "scale": "xscale"},
    {"orient": "left", "scale": "yscale"}
  ],
  "layout": {"columns":1},
  "marks": [
    {
      "type": "group",
      "name": "table1",
      "style": "cell",
      "title": {"text": "First Bar Plot", "frame": "group"},
      "encode": {
        "update": {"width": {"signal": "width"}, "height": {"signal": "height"}}
      },
      "marks": [
        {
          "type": "rect",
          "from": {"data": "table"},
          "encode": {
            "enter": {
              "x": {"scale": "xscale", "field": "category"},
              "width": {"scale": "xscale", "band": 1},
              "y": {"scale": "yscale", "field": "amount"},
              "y2": {"scale": "yscale", "value": 0}
            },
            "update": {"fill": {"value": "steelblue"}},
            "hover": {"fill": {"value": "red"}}
          }
        }
      ]
    },
    {
      "type": "group",
      "name": "table2",
      "style": "cell",
      "title": {"text": "Second Bar Plot"},
      "encode": {
        "update": {"width": {"signal": "width"}, "height": {"signal": "height"}}
      },
      "marks": [
        {
          "type": "rect",
          "from": {"data": "table"},
          "encode": {
            "enter": {
              "x": {"scale": "xscale", "field": "category"},
              "width": {"scale": "xscale", "band": 1},
              "y": {"scale": "yscale", "field": "amount"},
              "y2": {"scale": "yscale", "value": 0}
            },
            "update": {"fill": {"value": "steelblue"}},
            "hover": {"fill": {"value": "red"}}
          }
        }
      ]
    }
  ]
}

进一步阅读所有选项：

https://vega.github.io/vega/docs/layout/