strokedash1.vl

{
    "mark": {
        "strokeWidth": 1,
        "opacity": 0.6,
        "type": "line"
    },
    "data": {
        "url": "https://vega.github.io/vega-lite/data/stocks.csv"
    },
    "width": 350,
    "$schema": "https://vega.github.io/schema/vega-lite/v4.json",
    "encoding": {
        "strokeDash": {
            "field": "symbol",
            "type": "nominal"
        },
        "x": {
            "field": "date",
            "type": "temporal"
        },
        "y": {
            "field": "price",
            "type": "quantitative"
        }
    }
}