Matplotlib TickedStroke | Python Visualization

Introduction

In Matplotlib, patheffects can be used to alter how paths are drawn. TickedStroke is a type of patheffect that draws lines with a ticked style. This tutorial will guide you through the steps of creating TickedStroke in Matplotlib.

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Applying TickedStroke to paths

In this step, we will apply TickedStroke to paths.

import matplotlib.pyplot as plt
import matplotlib.patches as patches
import matplotlib.path as path
import matplotlib.patheffects as patheffects

fig, ax = plt.subplots(figsize=(6, 6))
path = path.Path.unit_circle()
patch = patches.PathPatch(path, facecolor='none', lw=2, path_effects=[
    patheffects.withTickedStroke(angle=-90, spacing=10, length=1)])

ax.add_patch(patch)
ax.axis('equal')
ax.set_xlim(-2, 2)
ax.set_ylim(-2, 2)

plt.show()

This code will create a unit circle with TickedStroke path effect.

Applying TickedStroke to lines

In this step, we will apply TickedStroke to lines.

fig, ax = plt.subplots(figsize=(6, 6))
ax.plot([0, 1], [0, 1], label="Line",
        path_effects=[patheffects.withTickedStroke(spacing=7, angle=135)])

nx = 101
x = np.linspace(0.0, 1.0, nx)
y = 0.3*np.sin(x*8) + 0.4
ax.plot(x, y, label="Curve", path_effects=[patheffects.withTickedStroke()])

ax.legend()

plt.show()

This code will create a line and a curve with TickedStroke path effect.

Applying TickedStroke to contour plots

In this step, we will apply TickedStroke to contour plots.

fig, ax = plt.subplots(figsize=(6, 6))

nx = 101
ny = 105

## Set up survey vectors
xvec = np.linspace(0.001, 4.0, nx)
yvec = np.linspace(0.001, 4.0, ny)

## Set up survey matrices.  Design disk loading and gear ratio.
x1, x2 = np.meshgrid(xvec, yvec)

## Evaluate some stuff to plot
obj = x1**2 + x2**2 - 2*x1 - 2*x2 + 2
g1 = -(3*x1 + x2 - 5.5)
g2 = -(x1 + 2*x2 - 4.5)
g3 = 0.8 + x1**-3 - x2

cntr = ax.contour(x1, x2, obj, [0.01, 0.1, 0.5, 1, 2, 4, 8, 16],
                  colors='black')
ax.clabel(cntr, fmt="%2.1f", use_clabeltext=True)

cg1 = ax.contour(x1, x2, g1, [0], colors='sandybrown')
plt.setp(cg1.collections,
         path_effects=[patheffects.withTickedStroke(angle=135)])

cg2 = ax.contour(x1, x2, g2, [0], colors='orangered')
plt.setp(cg2.collections,
         path_effects=[patheffects.withTickedStroke(angle=60, length=2)])

cg3 = ax.contour(x1, x2, g3, [0], colors='mediumblue')
plt.setp(cg3.collections,
         path_effects=[patheffects.withTickedStroke(spacing=7)])

ax.set_xlim(0, 4)
ax.set_ylim(0, 4)

plt.show()

This code will create a contour plot with TickedStroke path effect.

Direction/side of the ticks

In this step, we will change the side of the ticks.

fig, ax = plt.subplots(figsize=(6, 6))
line_x = line_y = [0, 1]
ax.plot(line_x, line_y, label="Line",
        path_effects=[patheffects.withTickedStroke(spacing=7, angle=135)])

ax.plot(line_x, line_y, label="Opposite side",
        path_effects=[patheffects.withTickedStroke(spacing=7, angle=-135)])

ax.legend()
plt.show()

This code will create a line with ticks on both sides.

Summary

This tutorial showed how to create TickedStroke in Matplotlib. By following these steps, you can apply TickedStroke to paths, lines, and contour plots. You can also adjust the direction/side of the ticks.

Creating TickedStroke in Matplotlib