# Datashader

### Visualizing some polynomial roots with Datashader

Last week-end I found this interesting tweet by sara: The above figure shows all the complex roots from the various polynomials of degree 10 with coefficients in the set $\left\{ -1, 1 \right\}$. It made me think of Bohemian matrix…

### Download some benchmark road networks for Shortest Paths algorithms

Updated September 26, 2022 bugfix The goal of this Python notebook is to download and prepare a suite of benchmark networks for some shortest path algorithms. We would like to experiment with some simple directed graphs with non-negative weights. We…

### Plotting population density with datashader

In this short post, we are using the Global Human Settlement Layer from the European Commission: This spatial raster dataset depicts the distribution of population, expressed as the number of people per cell. The downloaded file has a worldwide…

### Goldbach's Comet with Numba and Datashader

Updated Jul 29, 2021 This Python notebook is about computing and plotting Goldbach function. It requires some basic mathematical knowledge, nothing fancy! The main point is to perfom some computations with Numba and some efficient plotting with…

### Lunch break: plotting traffic injuries with datashader

Well I love the datashader Python package and I am always happy to use it on some interesting datasets. I recently came across a traffic injury database for french roads, which happens to have some geographical coordinates. This comes from the…

### Nighttime Lights with Rasterio and Datashader

daIn this post, we are going to plot some satellite GeoTIFF data in Python. The data is provided by NOAA (single GeoTIFF: F16_20100111-20110731_rad_v4.avg_vis.tif): The Operational Linescan System (OLS) flown on the Defense Meteorological Satellite…

### Symmetric Chaos with Datashader and Numba

Map equation and coefficient values are taken from here. Some mathematical explainations can be found here, by Mike Field and Martin Golubitsky. import numpy as np import pandas as pd import datashader as ds from datashader import transfer_functions…

### Plotting Hopalong attractor with Datashader and Numba

What is an attractor? Definition from wikipedia: In the mathematical field of dynamical systems, an attractor is a set of numerical values toward which a system tends to evolve, for a wide variety of starting conditions of the system. System values…