Vega-lite 热图向变量添加文本

Question

"data": {
"values": [
  {"x": 0, "y": 0, "z": 0},
  {"x": 1, "y": 0, "z": 1},
  {"x": 2, "y": 0, "z": 5},
  {"x": 2, "y": 0, "z": 10},
  {"x": 4, "y": 0, "z": 16},
  {"x": 0, "y": 1, "z": 1},
  {"x": 1, "y": 1, "z": 2},
  {"x": 2, "y": 1, "z": 5},
  {"x": 3, "y": 1, "z": 10},
  {"x": 5, "y": 1, "z": 26}
]},

如何向变量添加文本，例如“AVG:”？

织女星编辑器

Answer 1

您可以使用计算转换来创建特定格式的文本以显示在文本标记中。 例如（ 织女星编辑器）：

{
  "data": {
    "values": [
      {"x": 0, "y": 0, "z": 0},
      {"x": 1, "y": 0, "z": 1},
      {"x": 2, "y": 0, "z": 5},
      {"x": 2, "y": 0, "z": 10},
      {"x": 4, "y": 0, "z": 16},
      {"x": 0, "y": 1, "z": 1},
      {"x": 1, "y": 1, "z": 2},
      {"x": 2, "y": 1, "z": 5},
      {"x": 3, "y": 1, "z": 10},
      {"x": 5, "y": 1, "z": 26}
    ]
  },
  "transform": [
    {
      "aggregate": [{"op": "mean", "field": "z", "as": "z"}],
      "groupby": ["x", "y"]
    },
    {"calculate": "'avg: ' + datum.z", "as": "z"}
  ],
  "mark": "text",
  "encoding": {
    "x": {"field": "x", "type": "ordinal"},
    "y": {"field": "y", "type": "ordinal"},
    "text": {"field": "z", "type": "nominal"}
  },
  "width": 300,
  "height": 100
}