{
  "$schema": "urn:prism:schema:v1:spec",
  "title": "Metric stack (vconcat)",
  "vconcat": [
    {
      "$schema": "urn:prism:schema:v1:spec",
      "title": "Score",
      "data": {"values": [
        {"day": 1, "score": 0.40, "revenue": 12.0, "clicks": 100},
        {"day": 2, "score": 0.48, "revenue": 15.0, "clicks": 130},
        {"day": 3, "score": 0.55, "revenue": 18.0, "clicks": 175},
        {"day": 4, "score": 0.61, "revenue": 22.0, "clicks": 210}
      ]},
      "mark": "line",
      "encoding": {
        "x": {"field": "day",   "type": "quantitative"},
        "y": {"field": "score", "type": "quantitative"}
      }
    },
    {
      "$schema": "urn:prism:schema:v1:spec",
      "title": "Revenue",
      "data": {"values": [
        {"day": 1, "score": 0.40, "revenue": 12.0, "clicks": 100},
        {"day": 2, "score": 0.48, "revenue": 15.0, "clicks": 130},
        {"day": 3, "score": 0.55, "revenue": 18.0, "clicks": 175},
        {"day": 4, "score": 0.61, "revenue": 22.0, "clicks": 210}
      ]},
      "mark": "line",
      "encoding": {
        "x": {"field": "day",     "type": "quantitative"},
        "y": {"field": "revenue", "type": "quantitative"}
      }
    },
    {
      "$schema": "urn:prism:schema:v1:spec",
      "title": "Clicks",
      "data": {"values": [
        {"day": 1, "score": 0.40, "revenue": 12.0, "clicks": 100},
        {"day": 2, "score": 0.48, "revenue": 15.0, "clicks": 130},
        {"day": 3, "score": 0.55, "revenue": 18.0, "clicks": 175},
        {"day": 4, "score": 0.61, "revenue": 22.0, "clicks": 210}
      ]},
      "mark": "line",
      "encoding": {
        "x": {"field": "day",    "type": "quantitative"},
        "y": {"field": "clicks", "type": "quantitative"}
      }
    }
  ]
}