I am trying to understand/adapt the code at: Deploying Bokeh Apps — HoloViews 1.14.3 documentation. I’m using to animate a heatmap. I have the data in the proper format ie. the plots are in a dict where the keys are the date (‘heatmap_keys’) and the values are the heatmaps. My problem is using the DateSlider where I am trying to make it show the dates ie. the ‘heatmap_keys’ instead of just the index of the keys.
In the code below I have the slider values as a list of datetime objects, ‘slider_vals’. I do this so that the slider value displayed is the date of the heatmap being shown.
def modify_doc(doc): # Create HoloViews plot and attach the document hvplot = renderer.get_plot(dmap, doc) # Create a slider and play buttons def animate_update(): year = slider.value + 1 if year > end: year = start slider.value = year def slider_update(attrname, old, new): # Notify the HoloViews stream of the slider update stream.event(phase=new) slider_vals = [datetime.datetime.strptime(i,'%Y-%m-%d') for i in heatmap_keys] start, end = slider_vals, slider_vals[-1] slider = DateSlider(start=start, end=end, value=start, step=1, title="Phase" ,show_value=True, height=30, width=180, format='%Y-%m-%d') slider.on_change('value', slider_update) callback_id = None def animate(): global callback_id if button.label == '► Play': button.label = '❚❚ Pause' callback_id = doc.add_periodic_callback(animate_update, 80) else: button.label = '► Play' doc.remove_periodic_callback(callback_id) button = Button(label='► Play', width=60, height=30) button.on_click(animate) # Combine the holoviews plot and widgets in a layout plot = layout([ [hvplot.state], [slider, button]], sizing_mode='fixed') doc.add_root(plot) return doc
My problem is that when the ‘animate_update’ function is called I get an error:
TypeError: '>' not supported between instances of 'float' and 'datetime.datetime'
That’s because in the if statement ‘slider.value + 1’ becomes a float and is compared to ‘end’ which is a datetime object. What I think should happen is that ‘year’ should be the next key in the ‘slider_vals’ list but I don’t know how to make that happen. It looks like start,step, and end are meant to be integers and the it’s assumed the keys to the dict of plots can just be integers. Any guidance would be appreciated.