{
  "$schema": "https://vega.github.io/schema/vega/v5.json",
  "description": "Line chart with conditional axis ticks, labels, and grid.",
  "background": "white",
  "padding": 5,
  "width": 400,
  "height": 200,
  "style": "cell",
  "data": [
    {
      "name": "source_0",
      "url": "data/stocks.csv",
      "format": {"type": "csv", "parse": {"date": "date"}},
      "transform": [
        {"type": "filter", "expr": "datum.symbol==='GOOG'"},
        {
          "type": "filter",
          "expr": "inrange(time(datetime(year(datum[\"date\"]), 0, 1, 0, 0, 0, 0)), [time(datetime(2006, 0, 1, 0, 0, 0, 0)), time(datetime(2007, 0, 1, 0, 0, 0, 0))])"
        }
      ]
    }
  ],
  "marks": [
    {
      "name": "marks",
      "type": "line",
      "style": ["line"],
      "sort": {"field": "datum[\"date\"]"},
      "from": {"data": "source_0"},
      "encode": {
        "update": {
          "stroke": {"value": "#4c78a8"},
          "description": {
            "signal": "\"date: \" + (timeFormat(datum[\"date\"], '%b %d, %Y')) + \"; price: \" + (format(datum[\"price\"], \"\"))"
          },
          "x": {"scale": "x", "field": "date"},
          "y": {"scale": "y", "field": "price"},
          "defined": {
            "signal": "isValid(datum[\"date\"]) && isFinite(+datum[\"date\"]) && isValid(datum[\"price\"]) && isFinite(+datum[\"price\"])"
          }
        }
      }
    }
  ],
  "scales": [
    {
      "name": "x",
      "type": "time",
      "domain": {"data": "source_0", "field": "date"},
      "range": [0, {"signal": "width"}]
    },
    {
      "name": "y",
      "type": "linear",
      "domain": {"data": "source_0", "field": "price"},
      "range": [{"signal": "height"}, 0],
      "nice": true,
      "zero": true
    }
  ],
  "axes": [
    {
      "scale": "x",
      "orient": "bottom",
      "tickCount": 8,
      "gridScale": "y",
      "grid": true,
      "encode": {
        "grid": {
          "update": {
            "strokeDash": [
              {
                "test": "time(datetime(2012, month(datum[\"value\"]), date(datum[\"value\"]), 0, 0, 0, 0))===time(datetime(2012, 0, 1, 0, 0, 0, 0))",
                "value": []
              },
              {"value": [2, 2]}
            ]
          }
        }
      },
      "domain": false,
      "labels": false,
      "aria": false,
      "maxExtent": 0,
      "minExtent": 0,
      "ticks": false,
      "zindex": 0
    },
    {
      "scale": "y",
      "orient": "left",
      "gridScale": "x",
      "grid": true,
      "tickCount": {"signal": "ceil(height/40)"},
      "domain": false,
      "labels": false,
      "aria": false,
      "maxExtent": 0,
      "minExtent": 0,
      "ticks": false,
      "zindex": 0
    },
    {
      "scale": "x",
      "orient": "bottom",
      "grid": false,
      "title": "date",
      "tickCount": 8,
      "labelFlush": true,
      "labelOverlap": true,
      "encode": {
        "ticks": {
          "update": {
            "strokeDash": [
              {
                "test": "time(datetime(2012, month(datum[\"value\"]), date(datum[\"value\"]), 0, 0, 0, 0))===time(datetime(2012, 0, 1, 0, 0, 0, 0))",
                "value": []
              },
              {"value": [2, 2]}
            ]
          }
        },
        "labels": {
          "update": {
            "text": {
              "signal": "[timeFormat(datum.value, '%b'), timeFormat(datum.value, '%m') == '01' ? timeFormat(datum.value, '%Y') : '']"
            }
          }
        }
      },
      "zindex": 0
    },
    {
      "scale": "y",
      "orient": "left",
      "grid": false,
      "title": "price",
      "labelOverlap": true,
      "tickCount": {"signal": "ceil(height/40)"},
      "zindex": 0
    }
  ],
  "config": {
    "axis": {"domainColor": "#ddd", "tickColor": "#ddd"},
    "axisX": {
      "labelAlign": "left",
      "labelExpr": "[timeFormat(datum.value, '%b'), timeFormat(datum.value, '%m') == '01' ? timeFormat(datum.value, '%Y') : '']",
      "labelPadding": -24,
      "labelOffset": 4,
      "tickSize": 30,
      "gridDash": {
        "condition": {
          "test": {
            "field": "value",
            "timeUnit": "monthdate",
            "equal": {"month": 1, "date": 1}
          },
          "value": []
        },
        "value": [2, 2]
      },
      "tickDash": {
        "condition": {
          "test": {
            "field": "value",
            "timeUnit": "monthdate",
            "equal": {"month": 1, "date": 1}
          },
          "value": []
        },
        "value": [2, 2]
      }
    }
  }
}