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Vega-Lite templates

Bayesian Posterior Update

Prior → likelihood → posterior over a parameter θ.

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{
  "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
  "data": { "values": [
    {"theta":0.0,"prior":0.0,"like":0.0,"post":0.0},
    {"theta":0.1,"prior":0.5,"like":0.05,"post":0.06},
    {"theta":0.2,"prior":1.2,"like":0.18,"post":0.30},
    {"theta":0.3,"prior":2.0,"like":0.48,"post":1.0},
    {"theta":0.4,"prior":2.4,"like":0.95,"post":2.4},
    {"theta":0.5,"prior":2.0,"like":1.20,"post":2.5},
    {"theta":0.6,"prior":1.2,"like":0.95,"post":1.2},
    {"theta":0.7,"prior":0.5,"like":0.48,"post":0.30},
    {"theta":0.8,"prior":0.1,"like":0.18,"post":0.02},
    {"theta":0.9,"prior":0.0,"like":0.05,"post":0.0}
  ]},
  "transform":[
    {"fold":["prior","like","post"], "as":["dist","p"]}
  ],
  "mark":{"type":"line","interpolate":"monotone","strokeWidth":2.5},
  "encoding":{
    "x":{"field":"theta","type":"quantitative","title":"θ"},
    "y":{"field":"p","type":"quantitative","title":"Density"},
    "color":{"field":"dist","type":"nominal",
      "scale":{"domain":["prior","like","post"],"range":["#94a3b8","#dc2626","#3666ff"]},
      "legend":{"title":null}}
  },
  "width":480,"height":280
}