ValueError('y must be real') when plotting by + rasterize on a sparse dataset

[ahuang11]

Not entirely sure if this is datashader or hvplot so feel free to transfer over, but I'd expect this to work.

import hvplot.pandas
from bokeh.sampledata.penguins import data as df

df.hvplot.points(
    x="bill_length_mm",
    y="bill_depth_mm",
    by="species",
    rasterize=True
)

File ~/miniconda3/envs/census/lib/python3.12/site-packages/holoviews/operation/datashader.py:422, in aggregate._apply_datashader(self, dfdata, cvs_fn, agg_fn, agg_kwargs, x, y)
    417 with warnings.catch_warnings():
    418     warnings.filterwarnings(
    419         action='ignore', message='casting datetime64',
    420         category=FutureWarning
    421     )
--> 422     agg = cvs_fn(dfdata, x.name, y.name, agg_fn, **agg_kwargs)
    424 is_where_index = ds15 and isinstance(agg_fn, ds.where) and isinstance(agg_fn.column, rd.SpecialColumn)
    425 is_summary_index = isinstance(agg_fn, ds.summary) and "index" in agg

File ~/miniconda3/envs/census/lib/python3.12/site-packages/datashader/core.py:474, in Canvas.line(self, source, x, y, agg, axis, geometry, line_width, antialias)
    466     if not isinstance(non_cat_agg, (
    467         rd.any, rd.count, rd.max, rd.min, rd.sum, rd.summary, rd._sum_zero,
    468         rd._first_or_last, rd.mean, rd.max_n, rd.min_n, rd._first_n_or_last_n,
    469         rd._max_or_min_row_index, rd._max_n_or_min_n_row_index, rd.where,
    470     )):
    471         raise NotImplementedError(
    472             f"{type(non_cat_agg)} reduction not implemented for antialiased lines")
--> 474 return bypixel(source, self, glyph, agg, antialias=glyph.antialiased)

File ~/miniconda3/envs/census/lib/python3.12/site-packages/datashader/core.py:1333, in bypixel(source, canvas, glyph, agg, antialias)
   1330 source, dshape = _bypixel_sanitise(source, glyph, agg)
   1332 schema = dshape.measure
-> 1333 glyph.validate(schema)
   1334 agg.validate(schema)
   1335 canvas.validate()

File ~/miniconda3/envs/census/lib/python3.12/site-packages/datashader/glyphs/points.py:132, in _PointLike.validate(self, in_dshape)
    130     raise ValueError('x must be real')
    131 elif not isreal(in_dshape.measure[str(self.y)]):
--> 132     raise ValueError('y must be real')

ValueError: y must be real

[hoxbro]

I can't seem to recreate the following:

What are your versions? Can you try again and see if you still see the problem or paste in the output of hv.show_versions?