How to do interactive 2D scatter plot zoom / point selection in Vaex?

Question

I saw that it is possible to do it during the demo: https://youtu.be/2Tt0i823-ec?t=769

There, the presenter has a huge dataset, and can quickly zoom in by selecting a rectangle with the mouse.

I also saw the "Interactive Widgets" section of the tutorial: https://docs.vaex.io/en/latest/tutorial.html#Interactive-widgets

However, I was not able to easily replicate that setup. What are the minimal steps to achieve it?

On Ubuntu 19.04 vaex 2.0.2, I have tried:

python3 -m pip install --user vaex scipy pandas vaex-jupyter
jupyter nbextension enable --py widgetsnbextension
jupyter nbextension enable --py bqplot
jupyter nbextension enable --py ipyvolume
jupyter nbextension enable --py ipympl
jupyter nbextension enable --py ipyleaflet
jupyter nbextension enable --py ipyvuetify
jupyter notebook

Then I created a notebook and paste in the notebook:

import vaex
import vaex.jupyter
import numpy as np
import pylab as plt
%matplotlib inline
df = vaex.example()
df.plot_widget(df.x, df.y, f='log1p', backend='bqplot')

but all I get is no graph and the message:

Plot2dDefault(w=None, what='count(*)', x='x', y='y', z=None)

If instead I do:

df.plot(df.x, df.y, f='log1p')

then I do get an plot, but it is just a non-interactive image.

I also tried to git clone the notebook that is the source of the read the docs page: https://github.com/vaexio/vaex/blob/0247f0673c5c0473001b0b66adcbc716560536aa/docs/source/tutorial.ipynb but the result was the same.

My motivation is to find a plotting program that can handle large number of points as mentioned at: Large plot: ~20 million samples, gigabytes of data

Answer 1

Use virtualenv

Not sure why, but this fixed it. I think it is because the Jupyter executable was on Python 2 and could not find Python 3 extensions.

virtualenv --python=python3 .venv
. .venv/bin/activate
python3 -m pip install vaex scipy pandas vaex-jupyter
jupyter nbextension enable --py widgetsnbextension
jupyter nbextension enable --py bqplot
jupyter nbextension enable --py ipyvolume
jupyter nbextension enable --py ipympl
jupyter nbextension enable --py ipyleaflet
jupyter nbextension enable --py ipyvuetify
jupyter notebook

and inside a new notebook:

import vaex
df = vaex.example()
df.plot_widget(df.x, df.y, f='log1p', backend='bqplot')

and now I see the interactive widget with zoom!

Versions:

pandas==0.25.0
scipy==1.3.0
vaex==2.0.2
vaex-jupyter==0.3.0