Add_periodic_callback for bound function in Panel

I’m a new user of Panel, and I have a bound function created with pn.bind, like this:

magnitude = pnw.IntSlider(end=10, name='value', value=5, value_throttled=5)
cmap = pnw.RadioButtonGroup(name='cmap', value='viridis', 
                                 options=['viridis', 'plasma', 'inferno', 'magma', 'cividis'])

boundfn = pn.bind(random_imshow, magnitude=magnitude, sigma=3, colormap=cmap)
pane = pn.Row(pn.Column(magnitude, cmap), boundfn)

This provides a slider and a radio button group, and the random_imshow function is called with the right arguments each time any of these inputs change.

I would like to run this random_imshow function every second, updating the display, and using as parameters the latest values from the UI.

I thought that adding:

pn.state.add_periodic_callback(boundfn, period=1000)

would work, but it doesn’t seem to get called every second.

I naively assumed this would work, and am a bit stuck now, and am not sure where to go next.

Is there a way to get Panel to call this bound function every second, updating the screen? Or would I have to go deeper into Panel and try and link some of the underlying objects together somehow? I liked the simple way that pn.bind worked, and was hoping it would easily extend to refreshing regularly.

A full Jupyter notebook with my example code is available at - and that includes the definition of random_imshow which is not shown here for brevity.



you can do this:

cb = pn.state.add_periodic_callback(lambda: magnitude.param.trigger('value'), period=1000)


or may be better but not documented:

cb = pn.state.add_periodic_callback(pane[1]._replace_pane, period=1000)
1 Like

Thank you very much for the prompt replies - both of those work.



1 Like