vega-lite：如何将图例分成多列

Question

考虑以下设想的例子：

{
  "data": {"url": "data/cars.json"},
  "mark": "point",
  "encoding": {
    "x": {"field": "Horsepower","type": "quantitative"},
    "y": {"field": "Origin","type": "nominal"},
    "color": {"field": "Miles_per_Gallon","type": "ordinal"}
  }
}

数据集有Miles_per_Gallon的许多值，因此color图例将包含许多元素，并且会比图本身大得多。

有没有办法在多个列中显示此图例，而不是单个列？

Answer 1

您可以使用每加仑英里数作为定量变量。

{
  "data": {"url": "data/cars.json"},
  "mark": "point",
  "encoding": {
    "x": {"field": "Horsepower","type": "quantitative"},
    "y": {"field": "Origin","type": "nominal"},
    "color": {"field": "Miles_per_Gallon","type": "quantitative"}
  }
}