log tax wheel

spec.json

{
  "$schema": "https://vega.github.io/schema/vega/v5.json",
  "width": 400,
  "height": 400,
  "signals": [{"name": "radius", "value": 150}],
  "scales": [
    {
      "name": "angularScale",
      "type": "linear",
      "domain": [0, 1],
      "range": [0, 6.28318]
    },
    {
      "name": "angularScale2",
      "type": "linear",
      "domain": [0, 1],
      "range": [0, 6.28318]
    },
    {
      "name": "radiusScale",
      "type": "linear",
      "domain": [1, 9],
      "range": [0, {"signal": "radius"}]
    }
  ],
  "marks": [
    {
      "type": "arc",
      "from": {"data": "ticks"},
      "encode": {
        "enter": {
          "x": {"signal": "width / 2"},
          "y": {"signal": "height / 2"},
          "startAngle": {"field": "angle"},
          "endAngle": {"field": "angle"},
          "outerRadius": {"signal": "radius"},
          "innerRadius": {
            "signal": "radius - ((datum.value % 0.5 == 0 ) ? 10 : (datum.value % 0.25 == 0 ) ? 7 : 4)"
          },
          "stroke": {"value": "black"},
          "strokeWidth": {"value": 1}
        }
      }
    },
    {
      "type": "text",
      "from": {"data": "ticks"},
      "encode": {
        "enter": {
          "x": {"signal": "width / 2"},
          "y": {"signal": "height / 2"},
          "radius": {"signal": "radius - 15"},
          "theta": {"field": "angle"},
          "text": {"signal": "format(datum.value, '.3g')"},
          "align": {"signal": "'right'"},
          "baseline": {"value": "middle"},
          "fontSize": {"value": 10},
          "opacity": {
            "signal": "(datum.value < 2 || datum.value % 0.25 == 0 ) ? 1 : 0"
          },
          "angle": {"signal": "(datum.angle * 180 / PI - 90)"}
        }
      }
    },
    {
      "type": "arc",
      "from": {"data": "ticks2"},
      "encode": {
        "enter": {
          "x": {"signal": "width / 2"},
          "y": {"signal": "height / 2"},
          "startAngle": {"field": "angle"},
          "endAngle": {"field": "angle"},
          "outerRadius": {
            "signal": "radius + ((datum.value % 0.5 == 0 ) ? 10 : (datum.value % 0.25 == 0 ) ? 7 : 4)"
          },
          "innerRadius": {"signal": "radius"},
          "stroke": {"value": "black"},
          "strokeWidth": {"value": 1}
        }
      }
    },
    {
      "type": "text",
      "from": {"data": "ticks2"},
      "encode": {
        "enter": {
          "x": {"signal": "width / 2"},
          "y": {"signal": "height / 2"},
          "radius": {"signal": "radius + 15"},
          "theta": {"field": "angle"},
          "text": {"signal": "format(datum.value, '.3g')"},
          "align": {"signal": "'left'"},
          "baseline": {"value": "middle"},
          "fontSize": {"value": 10},
          "opacity": {
            "signal": "(datum.value < 2 || datum.value % 0.25 == 0 ) ? 1 : 0"
          },
          "angle": {"signal": "(datum.angle * 180 / PI - 90)"}
        }
      }
    }
  ],
  "data": [
    {
      "name": "ticks",
      "transform": [
        {"type": "sequence", "start": 1, "stop": 9.999, "step": 0.05},
        {
          "type": "formula",
          "expr": "scale('angularScale', log(datum.data)/log(10))",
          "as": "angle"
        },
        {"type": "formula", "expr": "datum.data", "as": "value"}
      ]
    },
    {
      "name": "ticks2",
      "transform": [
        {"type": "sequence", "start": 1, "stop": 9.999, "step": 0.05},
        {
          "type": "formula",
          "expr": "scale('angularScale2', log(datum.data)/log(10) - log(1.15)/log(10))",
          "as": "angle"
        },
        {"type": "formula", "expr": "datum.data", "as": "value"}
      ]
    }
  ]
}