Aster plot in Vega.js

aster.json

{
  "name": "Vega Visualization",
  "height": 250,
  "padding": "auto",
  "marks": [
    {
      "properties": {
        "update": {"fillOpacity": {"value": 1}},
        "hover": {"fillOpacity": {"value": 0.5}},
        "enter": {
          "innerRadius": {"value": 75},
          "stroke": {"value": "white"},
          "startAngle": {"field": "layout_start"},
          "x": {"mult": 0.5,"group": "width"},
          "outerRadius": {"field": "calcOuterRadius"},
          "endAngle": {"field": "layout_end"},
          "fill": {"field": "x","scale": "color"},
          "y": {"mult": 0.5,"group": "height"}
        }
      },
      "from": {
        "data": "table",
        "transform": [
          {"field": "y2","type": "pie"},
          {
            "field": "calcOuterRadius",
            "expr": "(250 - 75) * (datum.y/100.0) + 75",
            "type": "formula"
          }
        ]
      },
      "type": "arc"
    },
    {
      "properties": {
        "enter": {
          "innerRadius": {"value": 75},
          "stroke": {"value": "gray"},
          "startAngle": {"field": "layout_start"},
          "x": {"mult": 0.5,"group": "width"},
          "outerRadius": {"value": 250},
          "endAngle": {"field": "layout_end"},
          "y": {"mult": 0.5,"group": "height"}
        }
      },
      "from": {
        "data": "table",
        "transform": [
          {"field": "y2","type": "pie"},
          {
            "field": "calcOuterRadius",
            "expr": "(250 - 75) * (datum.y/100.0) + 75",
            "type": "formula"
          }
        ]
      },
      "type": "arc"
    }
  ],
  "data": [
    {
      "name": "table",
      "values": [
        {"x": "FIS","y2": 0.5,"group": 1,"y": 59},
        {"x": "MAR","y2": 0.5,"group": 1,"y": 24},
        {"x": "AO","y2": 1,"group": 1,"y": 98},
        {"x": "NP","y2": 1,"group": 1,"y": 60},
        {"x": "CS","y2": 1,"group": 1,"y": 74},
        {"x": "CP","y2": 1,"group": 1,"y": 70},
        {"x": "TR","y2": 1,"group": 1,"y": 42},
        {"x": "LIV","y2": 0.5,"group": 1,"y": 77},
        {"x": "ECO","y2": 0.5,"group": 1,"y": 88},
        {"x": "ICO","y2": 0.5,"group": 1,"y": 60},
        {"x": "LSP","y2": 0.5,"group": 1,"y": 65},
        {"x": "CW","y2": 1,"group": 1,"y": 71},
        {"x": "HAB","y2": 0.5,"group": 1,"y": 88},
        {"x": "SPP","y2": 0.5,"group": 1,"y": 83}
      ]
    }
  ],
  "scales": [
    {
      "name": "color",
      "range": [
        "#9E0041",
        "#C32F4B",
        "#E1514B",
        "#F47245",
        "#FB9F59",
        "#FEC574",
        "#FAE38C",
        "#EAF195",
        "#C7E89E",
        "#9CD6A4",
        "#6CC4A4",
        "#4D9DB4",
        "#4776B4",
        "#5E4EA1"
      ],
      "domain": {"data": "table","field": "x"},
      "type": "ordinal"
    }
  ],
  "width": 250,
  "legends": [{"title": "group","fill": "color"}]
}