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Matplotlib Cheatsheet

Matplotlib prepares 2D (and some 3D) graphics.

  • Matplotlib is the whole package. Pylab and matplotlib.pyplot (pyplot in the following) are modules in matplotlib.
  • Pyplot makes matplotlib work like MATLAB.
  • Pyplot provides the state-machine interface to the underlying plotting library (the matplotlib API in the matplotlib module).
  • Each pyplot function makes some change to a figure: eg, create a figure, create a plotting area in a figure, plot some lines in a plotting area, decorate the plot with labels, etc....
  • Pyplot is stateful, in that it keeps track of the current figure and plotting area, and the plotting functions are directed to the current axes.
  • Pylab combines the pyplot functionality (for plotting) with the numpy functionality (mathematics / arrays) in a single namespace, making that namespace (or environment) even more MATLAB-like.
  • The pyplot interface is generally preferred for non-interactive plotting (i.e., scripting).
  • The pylab interface is convenient for interactive calculations and plotting, as it minimizes typing.

Examples

import numpy as np
import matplotlib.pyplot as plt

# Compute the x and y coordinates for points on sine and cosine curves
x = np.arange(0, 3 * np.pi, 0.1)
y_sin = np.sin(x)
y_cos = np.cos(x)

# Set up a subplot grid that has height 2 and width 1,
# and set the first such subplot as active.
plt.subplot(2, 1, 1)

# Make the first plot
plt.plot(x, y_sin)
plt.title('Sine')

# Set the second subplot as active, and make the second plot.
plt.subplot(2, 1, 2)
plt.plot(x, y_cos)
plt.title('Cosine')

# Show the figure.
plt.show()