facet fails on arc

[mattijn]

Given the following vega-lite spec:

{
  "$schema": "https://vega.github.io/schema/vega-lite/v5.6.1.json",
  "data": {
    "values": [
      {"t": 0, "v": 2, "c": "foo"},
      {"t": 1, "v": 2.5, "c": "foo"},
      {"t": 2, "v": 3, "c": "foo"},
      {"t": 3, "v": 4, "c": "foo"},
      {"t": 4, "v": 5, "c": "foo"},
      {"t": 5, "v": 5.5, "c": "foo"},
      {"t": 6, "v": 4, "c": "foo"},
      {"t": 7, "v": 3, "c": "foo"},
      {"t": 0, "v": 2, "c": "bah"},
      {"t": 1, "v": 2.5, "c": "bah"},
      {"t": 2, "v": 3, "c": "bah"},
      {"t": 3, "v": 4, "c": "bah"},
      {"t": 4, "v": 5, "c": "bah"},
      {"t": 5, "v": 5.5, "c": "bah"},
      {"t": 6, "v": 4, "c": "bah"},
      {"t": 7, "v": 3, "c": "bah"}
    ]
  },
  "mark": {"type": "arc"},
  "encoding": {
    "color": {"field": "v", "type": "quantitative"},
    "column": {"field": "c", "type": "nominal"},
    "radius": {"field": "v", "type": "quantitative"},
    "theta": {"field": "t", "type": "nominal"}
  },

}

I see:

Open the Chart in the Vega Editor

It seems it is not possible to facet an arc-mark.

Removing the "column": {"field": "c", "type": "nominal"} gives a single chart:

Altair python code:

import altair as alt
import pandas as pd

base = pd.DataFrame(
    {"t": range(8),
     "v": [2, 2.5, 3, 4, 5, 5.5, 4, 3]}
)
cA = base.copy()
cA.loc[:, 'c'] = 'foo'
cB = base.copy()
cB.loc[:, 'c'] = 'bah'

source = pd.concat((cA, cB))
source.head()

arcs = alt.Chart(source).mark_arc().encode(theta="t:N", radius="v:Q", color="v:Q", column="c:N")
arcs

Related: #3729

[ChiaLingWeng]

for this issue, I added width and height in config and it works,
since I saw they are 0 in signal viewer, not sure if this info helps
{"width": 200,
"height": 200}