selection_heatmap.vg.json

{
  "$schema": "https://vega.github.io/schema/vega/v5.json",
  "background": "white",
  "padding": 5,
  "style": "cell",
  "data": [
    {
      "name": "highlight_store",
      "transform": [{"type": "collect", "sort": {"field": "_vgsid_"}}]
    },
    {
      "name": "source_0",
      "values": [
        {"actual": "A", "predicted": "A", "count": 13},
        {"actual": "A", "predicted": "B", "count": 0},
        {"actual": "A", "predicted": "C", "count": 0},
        {"actual": "B", "predicted": "A", "count": 0},
        {"actual": "B", "predicted": "B", "count": 10},
        {"actual": "B", "predicted": "C", "count": 6},
        {"actual": "C", "predicted": "A", "count": 0},
        {"actual": "C", "predicted": "B", "count": 0},
        {"actual": "C", "predicted": "C", "count": 9}
      ]
    },
    {
      "name": "data_0",
      "source": "source_0",
      "transform": [
        {"type": "identifier", "as": "_vgsid_"},
        {
          "type": "filter",
          "expr": "isValid(datum[\"count\"]) && isFinite(+datum[\"count\"])"
        }
      ]
    }
  ],
  "signals": [
    {"name": "x_step", "value": 40},
    {"name": "width", "update": "bandspace(domain('x').length, 0, 0) * x_step"},
    {"name": "y_step", "value": 40},
    {
      "name": "height",
      "update": "bandspace(domain('y').length, 0, 0) * y_step"
    },
    {
      "name": "unit",
      "value": {},
      "on": [
        {"events": "mousemove", "update": "isTuple(group()) ? group() : unit"}
      ]
    },
    {
      "name": "highlight",
      "update": "vlSelectionResolve(\"highlight_store\", \"union\", true, true)"
    },
    {
      "name": "highlight_tuple",
      "on": [
        {
          "events": [{"source": "scope", "type": "click"}],
          "update": "datum && item().mark.marktype !== 'group' && indexof(item().mark.role, 'legend') < 0 ? {unit: \"\", _vgsid_: (item().isVoronoi ? datum.datum : datum)[\"_vgsid_\"]} : null",
          "force": true
        },
        {"events": [{"source": "view", "type": "dblclick"}], "update": "null"}
      ]
    },
    {
      "name": "highlight_toggle",
      "value": false,
      "on": [
        {
          "events": [{"source": "scope", "type": "click"}],
          "update": "event.shiftKey"
        },
        {"events": [{"source": "view", "type": "dblclick"}], "update": "false"}
      ]
    },
    {
      "name": "highlight_modify",
      "on": [
        {
          "events": {"signal": "highlight_tuple"},
          "update": "modify(\"highlight_store\", highlight_toggle ? null : highlight_tuple, highlight_toggle ? null : true, highlight_toggle ? highlight_tuple : null)"
        }
      ]
    }
  ],
  "marks": [
    {
      "name": "marks",
      "type": "rect",
      "style": ["rect"],
      "interactive": true,
      "from": {"data": "data_0"},
      "encode": {
        "update": {
          "strokeWidth": {"value": 2},
          "fill": {"scale": "fill", "field": "count"},
          "stroke": [
            {
              "test": "length(data(\"highlight_store\")) && vlSelectionIdTest(\"highlight_store\", datum)",
              "value": "black"
            },
            {"value": null}
          ],
          "opacity": [
            {
              "test": "!length(data(\"highlight_store\")) || vlSelectionIdTest(\"highlight_store\", datum)",
              "value": 1
            },
            {"value": 0.5}
          ],
          "zindex": [
            {
              "test": "!length(data(\"highlight_store\")) || vlSelectionIdTest(\"highlight_store\", datum)",
              "value": 1
            },
            {"value": 0}
          ],
          "description": {
            "signal": "\"predicted: \" + (isValid(datum[\"predicted\"]) ? datum[\"predicted\"] : \"\"+datum[\"predicted\"]) + \"; actual: \" + (isValid(datum[\"actual\"]) ? datum[\"actual\"] : \"\"+datum[\"actual\"]) + \"; count: \" + (format(datum[\"count\"], \"\"))"
          },
          "x": {"scale": "x", "field": "predicted"},
          "width": {"scale": "x", "band": 1},
          "y": {"scale": "y", "field": "actual"},
          "height": {"scale": "y", "band": 1}
        }
      }
    }
  ],
  "scales": [
    {
      "name": "x",
      "type": "band",
      "domain": {"data": "data_0", "field": "predicted", "sort": true},
      "range": {"step": {"signal": "x_step"}},
      "paddingInner": 0,
      "paddingOuter": 0
    },
    {
      "name": "y",
      "type": "band",
      "domain": {"data": "data_0", "field": "actual", "sort": true},
      "range": {"step": {"signal": "y_step"}},
      "paddingInner": 0,
      "paddingOuter": 0
    },
    {
      "name": "fill",
      "type": "linear",
      "domain": {"data": "data_0", "field": "count"},
      "range": "heatmap",
      "interpolate": "hcl",
      "zero": false
    }
  ],
  "axes": [
    {
      "scale": "x",
      "orient": "bottom",
      "grid": false,
      "title": "predicted",
      "labelAlign": "right",
      "labelAngle": 270,
      "labelBaseline": "middle",
      "zindex": 1
    },
    {
      "scale": "y",
      "orient": "left",
      "grid": false,
      "title": "actual",
      "zindex": 1
    }
  ],
  "legends": [
    {
      "fill": "fill",
      "gradientLength": {"signal": "clamp(height, 64, 200)"},
      "title": "count",
      "encode": {"gradient": {"update": {"opacity": {"value": 1}}}}
    }
  ],
  "config": {
    "range": {"ramp": {"scheme": "yellowgreenblue"}},
    "axis": {"domain": false}
  }
}