{
    "$schema": "https://vega.github.io/schema/vega-lite/v4.json",
    "data": {
        "url": "https://vega.github.io/vega-lite/data/barley.json"
    },
    "encoding": {
        "color": {
            "field": "site",
            "type": "nominal"
        },
        "order": {
            "field": "siteOrder"
        },
        "x": {
            "aggregate": "sum",
            "field": "yield",
            "type": "quantitative"
        },
        "y": {
            "field": "variety",
            "type": "nominal"
        }
    },
    "mark": "bar",
    "transform": [
        {
            "as": "siteOrder",
            "calculate": "if(datum.site === 'University Farm', 0, if(datum.site === 'Grand Rapids', 1, 2))"
        }
    ]
}