{ "$schema": "https://vega.github.io/schema/vega-lite/v4.json", "description": "A scatterplot showing horsepower and miles per gallons with binned acceleration on opacity.", "data": {"url": "data/cars.json"}, "mark": "point", "encoding": { "x": {"field": "Horsepower", "type": "quantitative"}, "y": {"field": "Miles_per_Gallon", "type": "quantitative"}, "opacity": {"bin": true, "field": "Acceleration"} }}