{
  "$schema": "urn:prism:schema:v1:spec",
  "title": "Channel contribution (horizontal bar)",
  "data": {
    "name": "channel_contribution",
    "values": [
      {"channel": "paid_search", "delta": 0.42},
      {"channel": "organic",     "delta": 0.71},
      {"channel": "referral",    "delta": 0.18},
      {"channel": "display",     "delta": -0.26}
    ]
  },
  "mark": {"type": "bar", "orient": "horizontal"},
  "encoding": {
    "y": {"field": "channel", "type": "nominal"},
    "x": {"field": "delta",   "type": "quantitative"}
  }
}