Plotly backend doesn't update downsample1d on zoom #6649
Description
ALL software version info
(this library, plus any other relevant software, e.g. bokeh, python, notebook, OS, browser, etc should be added within the dropdown below.)
Software Version Info
annotated-types==0.7.0
anyio==4.9.0
anywidget==0.9.18
argon2-cffi==25.1.0
argon2-cffi-bindings==21.2.0
arrow==1.3.0
asttokens==3.0.0
async-lru==2.0.5
attrs==25.3.0
babel==2.17.0
beautifulsoup4==4.13.4
bleach==6.2.0
bokeh==3.7.3
bokeh_sampledata==2024.2
build==1.2.2.post1
certifi==2025.6.15
cffi==1.17.1
charset-normalizer==3.4.2
click==8.2.1
colorcet==3.1.0
comm==0.2.2
contourpy==1.3.2
cycler==0.12.1
datashader==0.18.1
debugpy==1.8.14
decorator==5.2.1
defusedxml==0.7.1
diskcache==5.6.3
docutils==0.21.2
executing==2.2.0
fastapi==0.115.12
fastjsonschema==2.21.1
fonttools==4.58.4
fqdn==1.5.1
h11==0.16.0
h5py==3.14.0
holoviews==1.21.0
httpcore==1.0.9
httptools==0.6.4
httpx==0.28.1
icalendar==6.3.1
idna==3.10
-e git+ssh://[email protected]/Innovoltive/InSpice.git@020f731cba1550419e825d0033351b32058bd01f#egg=InSpice
ipykernel==6.29.5
ipython==9.3.0
ipython_pygments_lexers==1.1.1
ipywidgets==8.1.7
isoduration==20.11.0
itsdangerous==2.2.0
jedi==0.19.2
Jinja2==3.1.6
json5==0.12.0
jsonpointer==3.0.0
jsonschema==4.24.0
jsonschema-specifications==2025.4.1
jupyter==1.1.1
jupyter-console==6.6.3
jupyter-events==0.12.0
jupyter-lsp==2.2.5
jupyter_bokeh==4.0.5
jupyter_client==8.6.3
jupyter_core==5.8.1
jupyter_server==2.16.0
jupyter_server_terminals==0.5.3
jupyterlab==4.4.4
jupyterlab_pygments==0.3.0
jupyterlab_server==2.27.3
jupyterlab_widgets==3.0.15
kiwisolver==1.4.8
linkify-it-py==2.0.3
llvmlite==0.44.0
loro==1.5.1
-e git+ssh://[email protected]/marimo-team/marimo.git@c7e4469976567805b4a82d17f93838cfa2253a4b#egg=marimo
Markdown==3.8
markdown-it-py==3.0.0
MarkupSafe==3.0.2
matplotlib==3.10.3
matplotlib-inline==0.1.7
mdit-py-plugins==0.4.2
mdurl==0.1.2
mistune==3.1.3
multipledispatch==1.0.0
narwhals==1.41.0
nbclient==0.10.2
nbconvert==7.16.6
nbformat==5.10.4
nest-asyncio==1.6.0
notebook==7.4.4
notebook_shim==0.2.4
numba==0.61.2
numpy==2.2.6
-e git+ssh://[email protected]/NyanCAD/Mosaic.git@8d019e95e3595ac7ef41b716292fd8a4c40452d5#egg=nyancad&subdirectory=python/nyancad
-e git+ssh://[email protected]/NyanCAD/Mosaic.git@8d019e95e3595ac7ef41b716292fd8a4c40452d5#egg=nyancad_server&subdirectory=python/nyancad-server
overrides==7.7.0
packaging==25.0
pandas==2.3.0
pandocfilters==1.5.1
panel==1.7.2
param==2.2.1
parso==0.8.4
pexpect==4.9.0
pillow==11.2.1
platformdirs==4.3.8
ply==3.11
prometheus_client==0.22.1
prompt_toolkit==3.0.51
psutil==7.0.0
psygnal==0.13.0
ptyprocess==0.7.0
pure_eval==0.2.3
pycparser==2.22
pyct==0.5.0
pydantic==2.11.7
pydantic_core==2.33.2
Pygments==2.19.1
pymdown-extensions==10.15
pyparsing==3.2.3
pyproject_hooks==1.2.0
python-dateutil==2.9.0.post0
python-dotenv==1.1.0
python-json-logger==3.3.0
pytz==2025.2
pyviz_comms==3.0.6
PyYAML==6.0.2
pyzmq==27.0.0
referencing==0.36.2
requests==2.32.4
rfc3339-validator==0.1.4
rfc3986-validator==0.1.1
rpds-py==0.26.0
scipy==1.16.0
Send2Trash==1.8.3
setuptools==80.9.0
six==1.17.0
sniffio==1.3.1
soupsieve==2.7
stack-data==0.6.3
starlette==0.46.2
terminado==0.18.1
tinycss2==1.4.0
tomlkit==0.13.2
toolz==1.0.0
tornado==6.5.1
tqdm==4.67.1
traitlets==5.14.3
types-python-dateutil==2.9.0.20250516
typing-inspection==0.4.1
typing_extensions==4.14.0
tzdata==2025.2
uc-micro-py==1.0.3
uri-template==1.3.0
urllib3==2.5.0
uvicorn==0.34.3
uvloop==0.21.0
watchfiles==1.1.0
wcwidth==0.2.13
webcolors==24.11.1
webencodings==0.5.1
websocket-client==1.8.0
websockets==15.0.1
widgetsnbextension==4.0.14
xarray==2025.6.1
xyzservices==2025.4.0
Description of expected behavior and the observed behavior
When using the bokeh backend, the data is dynamically resampled when you zoom in. However, with the plotly backend, no resampling is happening on zoom and you just see the downsampled points.
fwiw I only prefer the plotly backend because it allows you to easily zoom only in the X or Y axis while the bokeh box zoom is less sophisticated.
Complete, minimal, self-contained example code that reproduces the issue
import holoviews as hv
import numpy as np
import pandas as pd
import functools
from holoviews.operation.downsample import downsample1d
hv.extension('plotly')
#hv.extension('bokeh')
def _timeplot(data, cols=[]):
print("timeplot", data, cols)
traces = {k: hv.Curve(data, 'index', k).redim(**{k:'amplitude', 'index':'time'}) for k in cols}
if not cols: # hack
traces = {"dummy": hv.Scatter([])}
return downsample1d(hv.NdOverlay(traces, kdims='k'))
time = np.linspace(0, 10, 10000)
data = pd.DataFrame(
{
"sine_1hz": np.sin(2 * np.pi * 1 * time),
"sine_5hz": np.sin(2 * np.pi * 5 * time),
"sine_10hz": np.sin(2 * np.pi * 10 * time),
"noise": np.random.normal(0, 0.1, len(time)),
"index": time,
},
index=time,
)
plot = _timeplot(data, cols=["sine_1hz", "sine_5hz"])
plot.opts(responsive=True, height=500)Stack traceback and/or browser JavaScript console output
Screenshots or screencasts of the bug in action
- I may be interested in making a pull request to address this (I have no idea where to look though)