HoloMap update delayed only when inside a HoloViews pane

[paulmaxus]

Setup and package versions

I am rendering widget and pane inside a notebook (JupyterLab), but the same issue applies to the Panel Preview and when serving the application locally.

panel=1.2.1 jupyterlab=4.0.3 hvplot=0.8.4 holoviews=1.16.2 networkx=3.1

Description and minimal, self-contained example code

I am writing a panel application using JupyterLab. Specifically, I create a HoloMap with a number of hvplot.networkx plots that can be selected by a slider (the number of plots/frames is manageable). The underlying graph is the same, but edge alpha differs to create an effect of increasing edge strength.

The problem I encounter is that while the HoloMap widget updates smoothly when moving the slider, it is quite slow when rendered inside a pane (pn.panel).

On discourse I've uploaded a video with a more complex example: https://discourse.holoviz.org/t/holomap-gets-slow-when-used-inside-a-holoviews-pane/5985

However, the issue can be replicated well with the minimal example code below:

import panel as pn
import hvplot.networkx as hvnx
import networkx as nx
from holoviews import HoloMap

# number of hvplots
n = 20

# attributes for alpha
attributes = {str(i):i/n for i in range(n)}

# create minimal graph
G = nx.Graph()
G.add_edge('a', 'b', **attributes)

# create hvplots
pos = nx.spring_layout(G)
hvplots = {}
for i in attributes:
    nodes = hvnx.draw_networkx_nodes(G, pos)
    edges = hvnx.draw_networkx_edges(G, pos, alpha=i)
    hvplots[int(i)] = nodes * edges

# create HoloMap
hm = HoloMap(hvplots)

Now (in the notebook), I either create the widget as such by executing hm or inside a pane with pn.panel(hm)

Even for such a minimal HoloMap, the update speed difference is quite large.

[philippjfr]

Thanks for reporting, the issue here is that when displaying the HoloViews object directly it internally calls .embed() while otherwise it still triggers the embedding step but then triggers a re-render when you change the widget anyway because the embedded data isn't used.

[paulmaxus]

Thanks @philippjfr My solution for now is to convert it to a DynamicMap using Dynamic(). Much faster.