Vega-Lite地图没有显示，没有错误

Question

我修改了这个示例Vega-Lite地图绘制https://vega.github.io/vega-lite/examples/geo_trellis.html，但没有显示任何内容，也没有错误。

以下是代码

  "transform": [
    {
      "lookup": "id",
      "from": {
        "data": {
          "url": "data/us-10m.json",
          "format": {"type": "topojson", "feature": "states"}
        },
        "key": "id"
      },
      "as": "geo"
    }
  ],
  "projection": {"type": "albersUsa"},
  "mark": "geoshape",
  "encoding": {
    "shape": {"field": "geo", "type": "geojson"},
    "color": {"field": "count", "type": "quantitative"}
  }

Open the Chart in the Vega Editor

我不确定可能出了什么问题。谢谢你的帮助！

Answer 1

您的数据包含缺少"id"条目的行，这会导致联接数据中的geo条目为空。如果您过滤掉这些无效值，则对于定义的行(vega editor)，它将按预期工作：

"transform": [
    {"filter": "isValid(datum.id)"},
    {
      "lookup": "id",
      "from": {
        "data": {
          "url": "data/us-10m.json",
          "format": {"type": "topojson", "feature": "states"}
        },
        "key": "id"
      },
      "as": "geo"
    }
  ],

​

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