Weekly Temperature Example

Weekly weather data depicting ranges of record temperatures (light gray), normal temperatures (dark gray), actual temperatures (solid black) and forecasted temperatures (black barbells, with thick ends indicating forecasted ranges for high and low values).

Vega JSON Specification <>

{
  "$schema": "https://vega.github.io/schema/vega/v3.0.json",
  "width": 250,
  "height": 200,

  "data": [
    {
      "name": "weather",
      "url": "data/weather.json"
    },
    {
      "name": "actual",
      "source": "weather",
      "transform": [{"type":"filter", "expr":"datum.actual"}]
    },
    {
      "name": "forecast",
      "source": "weather",
      "transform": [{"type":"filter", "expr":"datum.forecast"}]
    }
  ],

  "scales": [
    {
      "name": "x",
      "type": "band",
      "range": "width",
      "padding": 0.1, "round": true,
      "domain": {"data": "weather", "field": "id"}
    },
    {
      "name": "y",
      "type": "linear",
      "range": "height",
      "nice": true, "zero": false, "round": true,
      "domain": {
        "data": "weather",
        "fields": ["record.low", "record.high"]
      }
    }
  ],

  "axes": [
    {
      "orient": "right",
      "scale": "y",
      "tickCount": 3,
      "tickSize": 0,
      "labelPadding": 0,
      "grid": true,
      "domain": false,
      "zindex": 1,
      "encode": {
        "grid": {"enter": {"stroke": {"value": "white"}}}
      }
    }
  ],

  "marks": [
    {
      "type": "text",
      "from": {"data": "weather"},
      "encode": {
        "enter": {
          "x": {"scale": "x", "field": "id"},
          "dx": {"scale": "x", "band": 0.5},
          "y": {"value": 0},
          "fill": {"value": "#000"},
          "text": {"field": "day"},
          "align": {"value": "center"},
          "baseline": {"value": "bottom"}
        }
      }
    },
    {
      "type": "rect",
      "from": {"data": "weather"},
      "encode": {
        "enter": {
          "x": {"scale": "x", "field": "id"},
          "width": {"scale": "x", "band": 1, "offset": -1},
          "y": {"scale": "y", "field": "record.low"},
          "y2": {"scale": "y", "field": "record.high"},
          "fill": {"value": "#ccc"}
        }
      }
    },
    {
      "type": "rect",
      "from": {"data": "weather"},
      "encode": {
        "enter": {
          "x": {"scale": "x", "field": "id"},
          "width": {"scale": "x", "band": 1, "offset": -1},
          "y": {"scale": "y", "field": "normal.low"},
          "y2": {"scale": "y", "field": "normal.high"},
          "fill": {"value": "#999"}
        }
      }
    },
    {
      "type": "rect",
      "from": {"data": "actual"},
      "encode": {
        "enter": {
          "x": {"scale": "x", "field": "id", "offset": 4},
          "width": {"scale": "x", "band": 1, "offset": -8},
          "y": {"scale": "y", "field": "actual.low"},
          "y2": {"scale": "y", "field": "actual.high"},
          "fill": {"value": "#000"}
        }
      }
    },
    {
      "type": "rect",
      "from": {"data": "forecast"},
      "encode": {
        "enter": {
          "x": {"scale": "x", "field": "id", "offset": 9},
          "width": {"scale": "x", "band": 1, "offset": -18},
          "y": {"scale": "y", "field": "forecast.low.low"},
          "y2": {"scale": "y", "field": "forecast.high.high"},
          "fill": {"value": "#000"}
        }
      }
    },
    {
      "type": "rect",
      "from": {"data": "forecast"},
      "encode": {
        "enter": {
          "x": {"scale": "x", "field": "id", "offset": 4},
          "width": {"scale": "x", "band": 1, "offset": -8},
          "y": {"scale": "y", "field": "forecast.low.low"},
          "y2": {"scale": "y", "field": "forecast.low.high"},
          "fill": {"value": "#000"}
        }
      }
    },
    {
      "type": "rect",
      "from": {"data": "forecast"},
      "encode": {
        "enter": {
          "x": {"scale": "x", "field": "id", "offset": 4},
          "width": {"scale": "x", "band": 1, "offset": -8},
          "y": {"scale": "y", "field": "forecast.high.low"},
          "y2": {"scale": "y", "field": "forecast.high.high"},
          "fill": {"value": "#000"}
        }
      }
    }
  ]
}