Vegalite忽略NaN与空值实现折线图无断点连续显示方法咨询

你需要在现有配置的spec节点下新增transform过滤规则，针对每个重复渲染的指标字段单独过滤无效值即可，完整配置如下：

{
  "title": "Blood Panel Data",  
  "width": 600,
  "height": 300,
  "config": {
    "axis": {
      "grid": true,
      "gridColor": "DarkSlateGrey",
      "background": "white"
    }
  },
  "repeat": {
    "layer": ["Cholesterol","Triglycerides","HDL Chol","LDL Chol","Non-HDL","Cholesterol/HDL-C Ratio"]
  },
  "spec": {
    "transform": [
      {"filter": "isValid(datum[repeat.layer])"}
    ],
    "mark" : {
      "type" : "line",
      "interpolate": "monotone",
      "point": true
    },
    "encoding": {
      "x": {"field": "Date", "type": "temporal"},
      "y": {
        "field": {"repeat": "layer"},
        "type": "quantitative",
        "title": "Value"
      },
      "color": { "datum": {"repeat": "layer"}, "type": "nominal" }
    }
  }
}

配置说明 #

• 新增的transform配置中使用VegaLite内置的isValid()函数，可自动排除null、NaN、空字符串三类无效值
• datum[repeat.layer]会动态匹配当前重复图层对应的胆固醇指标字段，实现每个指标单独过滤自身的空值，不会误删其他指标的有效数据
• 过滤后每个指标仅保留有有效值的点位，折线会自动跨过空值对应的日期直接连接相邻有效点位，不会出现断口

内容的提问来源于stack exchange，提问作者Karlstens