This article demonstrates matplotlib's animation module by animating marker particles in a fluid flow around a cylinder. It's a bit long because it ties together a number of different ideas:

• stream functions
• numerical integration
• plotting and animation

Before we really start, let's copy a function from a ...

I often need to save a series of arrays in which one dimension varies in length---sometimes called a ragged array [1]. For example, I'm running particle tracking experiments, and I need to save the 2D coordinates of all particles in each video frame. The number of particles in each ...

Fluid mechanics lends itself to some beautiful visualizations and images. I won't cover anything too complicated here, just potential flow, which any undergrad who has taken a fluid mechanics course should be (at least somewhat) familiar with.

I won't really cover the math or theory here; I'm ...

Let's say you have some continuous data with a continuous error (or variance) measurement. Typically, you would just call matplotlib's errorbar function:

import numpy as np
import matplotlib.pyplot as plt

x = np.linspace(0, 2 * np.pi)
y_sin = np.sin(x)
y_cos = np.cos(x)
plt.errorbar ...

When plotting a series of lines, it's nice to pull a series of colors from a colormap (especially if there's some sequential relationship between lines). In fact, this has been asked (and answered) multiple times on the Matplotlib mailing list (e.g., [1] and [2]) and on StackOverflow ...