Join styles and cap styles

This example demonstrates the available join styles and cap styles.

Both are used in Line2D and various Collections from matplotlib.collections as well as some functions that create these, e.g. plot.

Join styles

Join styles define how the connection between two line segments is drawn.

See the respective solid_joinstyle, dash_joinstyle or joinstyle parameters.

import numpy as np
import matplotlib.pyplot as plt


def plot_angle(ax, x, y, angle, style):
    phi = np.radians(angle)
    xx = [x + .5, x, x + .5*np.cos(phi)]
    yy = [y, y, y + .5*np.sin(phi)]
    ax.plot(xx, yy, lw=12, color='tab:blue', solid_joinstyle=style)
    ax.plot(xx, yy, lw=1, color='black')
    ax.plot(xx[1], yy[1], 'o', color='tab:red', markersize=3)


fig, ax = plt.subplots(figsize=(8, 6))
ax.set_title('Join style')

for x, style in enumerate(['miter', 'round', 'bevel']):
    ax.text(x, 5, style)
    for y, angle in enumerate([20, 45, 60, 90, 120]):
        plot_angle(ax, x, y, angle, style)
        if x == 0:
            ax.text(-1.3, y, f'{angle} degrees')
ax.text(1, 4.7, '(default)')

ax.set_xlim(-1.5, 2.75)
ax.set_ylim(-.5, 5.5)
ax.set_axis_off()
plt.show()

Cap styles

Cap styles define how the the end of a line is drawn.

See the respective solid_capstyle, dash_capstyle or capstyle parameters.

fig, ax = plt.subplots(figsize=(8, 2))
ax.set_title('Cap style')

for x, style in enumerate(['butt', 'round', 'projecting']):
    ax.text(x+0.25, 1, style, ha='center')
    xx = [x, x+0.5]
    yy = [0, 0]
    ax.plot(xx, yy, lw=12, color='tab:blue', solid_capstyle=style)
    ax.plot(xx, yy, lw=1, color='black')
    ax.plot(xx, yy, 'o', color='tab:red', markersize=3)
ax.text(2.25, 0.7, '(default)', ha='center')

ax.set_ylim(-.5, 1.5)
ax.set_axis_off()

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References

The use of the following functions, methods, classes and modules is shown in this example:

import matplotlib
matplotlib.axes.Axes.plot
matplotlib.pyplot.plot

Out:

<function plot at 0x7fba54a7a9d0>