When using rasterize=True with datashader, how do I get transparency where count=0 to see the underlying tile?

Question

Currently, when I do this:

import pandas as pd
import hvplot.pandas

df = pd.util.testing.makeDataFrame()
plot = df.hvplot.points('A', 'B', tiles=True, rasterize=True, geo=True,
                        aggregator='count')

I can't see the underlying tile source.

Answer 1

To see the underlying tile source philippjfr suggested setting the color bar limits slightly higher than 0 and set the min clipping_colors to transparent:

plot = plot.redim.range(**{'Count': (0.25, 1)})
plot = plot.opts('Image', clipping_colors={'min': 'transparent'})

Now the underlying tile source is viewable.

Full Code:

import pandas as pd
import hvplot.pandas

df = pd.util.testing.makeDataFrame()
plot = df.hvplot.points('A', 'B', tiles=True, rasterize=True, geo=True,
                        aggregator='count')

plot = plot.redim.range(**{'Count': (0.25, 1)})
plot = plot.opts('Image', clipping_colors={'min': 'transparent'})
plot