{ "transform": [ { "groupby": [ "date" ], "value": "price", "pivot": "symbol" } ], "data": { "url": "https://vega.github.io/vega-lite/data/stocks.csv" }, "repeat": { "layer": [ "AAPL", "AMZN", "GOOG", "IBM", "MSFT" ] }, "spec": { "layer": [ { "mark": { "strokeWidth": 4, "stroke": "white", "type": "line" }, "encoding": { "x": { "field": "date", "type": "temporal" }, "y": { "field": { "repeat": "layer" }, "title": "price", "type": "quantitative" } } }, { "mark": "line", "encoding": { "stroke": { "type": "nominal", "datum": { "repeat": "layer" } }, "x": { "field": "date", "type": "temporal" }, "y": { "field": { "repeat": "layer" }, "title": "price", "type": "quantitative" } } } ] }, "$schema": "https://vega.github.io/schema/vega-lite/v4.json", "description": "Multi-series Line Chart with Halo. Use pivot and repeat-layer as a workaround to facet groups of lines and their halo strokes. See https://github.com/vega/vega-lite/issues/6192 for more discussion." }