Facetted Cars Scatterplot

facetted_scatterplot.vl.json

{
  "$schema": "https://vega.github.io/schema/vega-lite/v4.json",
  "data": {"url": "data/cars.json"},
  "mark": {"type": "point", "tooltip": true},
  "encoding": {
    "x": {"field": "Horsepower", "type": "quantitative"},
    "y": {"field": "Miles_per_Gallon", "type": "quantitative"},
    "color": {"field": "Origin", "type": "nominal"},
    "opacity": {"value": 0.5},
    "row": {"field": "Origin", "type": "ordinal"}
  }
}