matplotx

Some useful extensions for Matplotlib.

This package includes some useful or beautiful extensions to Matplotlib. Most of those features could be in Matplotlib itself, but I haven't had time to PR yet. If you're eager, let me know and I'll support the effort.

Install with

pip install matplotx[all]

and use in Python with

import matplotx

See below for what matplotx can do.

Clean line plots (dufte)

matplotlib	matplotx.styles.dufte, matplotx.ylabel_top, matplotx.line_labels	matplotx.styles.duftify(matplotx.styles.dracula)

The middle plot is created with

import matplotlib.pyplot as plt
import matplotx
import numpy as np

# create data
rng = np.random.default_rng(0)
offsets = [1.0, 1.50, 1.60]
labels = ["no balancing", "CRV-27", "CRV-27*"]
x0 = np.linspace(0.0, 3.0, 100)
y = [offset * x0 / (x0 + 1) + 0.1 * rng.random(len(x0)) for offset in offsets]

# plot
with plt.style.context(matplotx.styles.dufte):
    for yy, label in zip(y, labels):
        plt.plot(x0, yy, label=label)
    plt.xlabel("distance [m]")
    matplotx.ylabel_top("voltage [V]")  # move ylabel to the top, rotate
    matplotx.line_labels()  # line labels to the right
    plt.show()

The three matplotx ingredients are:

• matplotx.styles.dufte: A minimalistic style
• matplotx.ylabel_top: Rotate and move the the y-label
• matplotx.line_labels: Show line labels to the right, with the line color

You can also "duftify" any other style (see below) with

matplotx.styles.duftify(matplotx.styles.dracula)

Further reading and other styles:

• Remove to improve: data-ink ratio

  

• Cereblog, Remove to improve: Line Graph Edition

• Show the Data - Maximize the Data Ink Ratio

• Randal S. Olson's blog entry

• prettyplotlib

• Wikipedia: Chartjunk

Clean bar plots

matplotlib	dufte	dufte with matplotx.show_bar_values()

The right plot is created with

import matplotlib.pyplot as plt
import matplotx

labels = ["Australia", "Brazil", "China", "Germany", "Mexico", "United\nStates"]
vals = [21.65, 24.5, 6.95, 8.40, 21.00, 8.55]
xpos = range(len(vals))

with plt.style.context(matplotx.styles.dufte_bar):
    plt.bar(xpos, vals)
    plt.xticks(xpos, labels)
    matplotx.show_bar_values("{:.2f}")
    plt.title("average temperature [°C]")
    plt.show()

The two matplotx ingredients are:

• matplotx.styles.dufte_bar: A minimalistic style for bar plots
• matplotx.show_bar_values: Show bar values directly at the bars

Extra styles

matplotx contains numerous extra color schemes, e.g., Dracula, Nord, gruvbox, and Solarized, the revised Tableau colors.

import matplotlib.pyplot as plt
import matplotx

# use everywhere:
plt.style.use(matplotx.styles.dracula)

# use with context:
with plt.style.context(matplotx.styles.dracula):
    pass

See here for a full list of extra styles

Other styles:

• John Garrett, Science Plots
• Dominik Haitz, Cyberpunk style
• Dominik Haitz, Matplotlib stylesheets
• Carlos da Costa, The Grand Budapest Hotel
• Danny Antaki, vaporwave aesthetics
• QuantumBlack Labs, QuantumBlack

Smooth contours

plt.contourf	matplotx.contours()

Sometimes, the sharp edges of contour[f] plots don't accurately represent the smoothness of the function in question. Smooth contours, contours(), serves as a drop-in replacement.

import matplotlib.pyplot as plt
import matplotx


def rosenbrock(x):
    return (1.0 - x[0]) ** 2 + 100.0 * (x[1] - x[0] ** 2) ** 2


im = matplotx.contours(
    rosenbrock,
    (-3.0, 3.0, 200),
    (-1.0, 3.0, 200),
    log_scaling=True,
    cmap="viridis",
    outline="white",
)
plt.gca().set_aspect("equal")
plt.colorbar(im)
plt.show()

Contour plots for functions with discontinuities

plt.contour	matplotx.contour(max_jump=1.0)

Matplotlib has problems with contour plots of functions that have discontinuities. The software has no way to tell discontinuities and very sharp, but continuous cliffs apart, and contour lines will be drawn along the discontinuity.

matplotx improves upon this by adding the parameter max_jump. If the difference between two function values in the grid is larger than max_jump, a discontinuity is assumed and no line is drawn. Similarly, min_jump can be used to highlight the discontinuity.

As an example, take the function imag(log(Z)) for complex values Z. Matplotlib's contour lines along the negative real axis are wrong.

import matplotlib.pyplot as plt
import numpy as np

import matplotx

x = np.linspace(-2.0, 2.0, 100)
y = np.linspace(-2.0, 2.0, 100)

X, Y = np.meshgrid(x, y)
Z = X + 1j * Y

vals = np.imag(np.log(Z))

# plt.contour(X, Y, vals, levels=[-2.0, -1.0, 0.0, 1.0, 2.0])  # draws wrong lines

matplotx.contour(X, Y, vals, levels=[-2.0, -1.0, 0.0, 1.0, 2.0], max_jump=1.0)
matplotx.discontour(X, Y, vals, min_jump=1.0, linestyle=":", color="r")

plt.gca().set_aspect("equal")
plt.show()

Relevant discussions:

• matplotlib/issues/21348

spy plots (betterspy)

Show sparsity patterns of sparse matrices or write them to image files.

Example:

import matplotx
from scipy import sparse

A = sparse.rand(20, 20, density=0.1)

# show the matrix
plt = matplotx.spy(
    A,
    # border_width=2,
    # border_color="red",
    # colormap="viridis"
)
plt.show()

# or save it as png
matplotx.spy(A, filename="out.png")

no colormap	viridis

There is a command-line tool that can be used to show matrix-market or Harwell-Boeing files:

matplotx spy msc00726.mtx [out.png]

See matplotx spy -h for all options.

License

This software is published under the MIT license.