Sorted Row + Column with `sort` argument - Faceted Chart does not show data correctly

[tonylee3399]

Hi peeps,

I am running the code with the following environment:

• Python version: 3.7.4 (default, Oct 24 2019, 16:20:49) [Clang 11.0.0 (clang-1100.0.33.8)]
• Altair version: 4.1.0

It seems to me that the faceted chart does not show correctly if I facet it by Row and Column and throwing sort argument. I have looked into other question and tried the sort argument with altair.Row and altair.Column. I'd really appreciate if you could point out something I am missing here. The following code would reproduce the issue:

Thanks!

import pandas as pd
import altair as alt
import sys
from io import StringIO

print(f"Python Version: {sys.version}")
print(f"Altair version: {alt.__version__}")

selection = alt.selection_single(on='mouseover')
w = 100
h = 100

x_domain = (-100, 100)
y_domain = (-200, 200)

data = """	x	y	Project	Stage
0	-10.540327	61.649657999999995	P1	S2
1	32.379704	-130.71579599999998	P1	S2
2	-2.620516	71.260701	P1	S2
3	13.978546	31.711221000000002	P1	S4
4	41.391873	88.070636	P1	S4
5	-0.303671	-84.376145	P1	S4
6	-65.370553	-7.694756	P2	S3
7	9.062894	177.233938	P2	S3
8	17.029269	-100.364923	P2	S3
9	13.354712	73.78603100000001	P2	S2
10	18.781817999999998	-109.3554	P2	S2
11	67.189193	113.94348000000001	P2	S2
12	8.762746	128.735548	P2	S1
13	59.287251	11.017662	P2	S1
14	-2.4981430000000002	-166.897776	P2	S1
15	1.1900870000000001	-82.309501	P3	S3
16	21.938575	-118.20861699999999	P3	S3
17	45.414544	122.49246000000001	P3	S3
18	-36.322626	-63.310702	P3	S2
19	53.568994999999994	141.37641100000002	P3	S2
20	26.129929999999998	153.706601	P3	S2
21	-3.9384330000000003	102.90164399999999	P3	S6
22	-8.198288	137.616797	P3	S6
23	-8.240618	-146.80676	P3	S6
24	15.193395	25.697023	P3	S5
25	20.886185	68.356337	P3	S5
26	-22.101129999999998	89.639481	P3	S5"""

exp = pd.read_csv(StringIO(data), sep='\t')
base = alt.Chart(exp)

point = base.mark_point().encode(
    alt.X('x:Q', scale=alt.Scale(domain=x_domain)),
    alt.Y('y:Q', scale=alt.Scale(domain=y_domain)),
    tooltip=['x', 'y'],
    color='Stage:N'
).properties(
    width=w, height=h
).facet(
    row=alt.Row('Project:N'),
    column=alt.Column('Stage:N')
).properties(
    title='Correct Data in Faceted Chart'
).configure_title(
    orient='top', anchor='middle', color='blue', fontSize=16
)
point.display()

point2 = base.mark_point().encode(
    alt.X('x:Q', scale=alt.Scale(domain=x_domain)),
    alt.Y('y:Q', scale=alt.Scale(domain=y_domain)),
    tooltip=['x', 'y'],
    color='Stage:N'
).properties(
    width=w, height=h
).facet(
    row=alt.Row('Project:N', sort=['P1', 'P2', 'P3']),
    column=alt.Column('Stage:N', sort=['S1', 'S2', 'S3', 'S4', 'S5', 'S6'])
).properties(
    title='Wrong Data in Faceted Chart'
).configure_title(
    orient='top', anchor='middle', color='red', fontSize=16
)
point2.display()

Data Description

Expected Plot

Data is misaligned after throwing sort argument

[jakevdp]

It looks like a Vega-Lite bug. I'd suggest finding a simpler vega-lite repro of the issue, and filing a bug there.

[leshaker]

same problem here. Any news on this from vega-lite?

[joelostblom]

Closing this as there is nothing to do from the Altair side of things here. Please open an issue in the VL repo for this and feel free to link it here. Once the functionality has been implemented in VL, it will be in an upcoming Altair release.