ticks_and_spines example code: tick-locators.py

(Source code, png, pdf)

"""
Show the different tick locators
"""

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


# Setup a plot such that only the bottom spine is shown
def setup(ax):
    ax.spines['right'].set_color('none')
    ax.spines['left'].set_color('none')
    ax.yaxis.set_major_locator(ticker.NullLocator())
    ax.spines['top'].set_color('none')
    ax.xaxis.set_ticks_position('bottom')
    ax.tick_params(which='major', width=1.00)
    ax.tick_params(which='major', length=5)
    ax.tick_params(which='minor', width=0.75)
    ax.tick_params(which='minor', length=2.5)
    ax.set_xlim(0, 5)
    ax.set_ylim(0, 1)
    ax.patch.set_alpha(0.0)


plt.figure(figsize=(8, 6))
n = 8

# Null Locator
ax = plt.subplot(n, 1, 1)
setup(ax)
ax.xaxis.set_major_locator(ticker.NullLocator())
ax.xaxis.set_minor_locator(ticker.NullLocator())
ax.text(0.0, 0.1, "NullLocator()", fontsize=14, transform=ax.transAxes)

# Multiple Locator
ax = plt.subplot(n, 1, 2)
setup(ax)
ax.xaxis.set_major_locator(ticker.MultipleLocator(0.5))
ax.xaxis.set_minor_locator(ticker.MultipleLocator(0.1))
ax.text(0.0, 0.1, "MultipleLocator(0.5)", fontsize=14,
        transform=ax.transAxes)

# Fixed Locator
ax = plt.subplot(n, 1, 3)
setup(ax)
majors = [0, 1, 5]
ax.xaxis.set_major_locator(ticker.FixedLocator(majors))
minors = np.linspace(0, 1, 11)[1:-1]
ax.xaxis.set_minor_locator(ticker.FixedLocator(minors))
ax.text(0.0, 0.1, "FixedLocator([0, 1, 5])", fontsize=14,
        transform=ax.transAxes)

# Linear Locator
ax = plt.subplot(n, 1, 4)
setup(ax)
ax.xaxis.set_major_locator(ticker.LinearLocator(3))
ax.xaxis.set_minor_locator(ticker.LinearLocator(31))
ax.text(0.0, 0.1, "LinearLocator(numticks=3)",
        fontsize=14, transform=ax.transAxes)

# Index Locator
ax = plt.subplot(n, 1, 5)
setup(ax)
ax.plot(range(0, 5), [0]*5, color='White')
ax.xaxis.set_major_locator(ticker.IndexLocator(base=.5, offset=.25))
ax.text(0.0, 0.1, "IndexLocator(base=0.5, offset=0.25)",
        fontsize=14, transform=ax.transAxes)

# Auto Locator
ax = plt.subplot(n, 1, 6)
setup(ax)
ax.xaxis.set_major_locator(ticker.AutoLocator())
ax.xaxis.set_minor_locator(ticker.AutoMinorLocator())
ax.text(0.0, 0.1, "AutoLocator()", fontsize=14, transform=ax.transAxes)

# MaxN Locator
ax = plt.subplot(n, 1, 7)
setup(ax)
ax.xaxis.set_major_locator(ticker.MaxNLocator(4))
ax.xaxis.set_minor_locator(ticker.MaxNLocator(40))
ax.text(0.0, 0.1, "MaxNLocator(n=4)", fontsize=14, transform=ax.transAxes)

# Log Locator
ax = plt.subplot(n, 1, 8)
setup(ax)
ax.set_xlim(10**3, 10**10)
ax.set_xscale('log')
ax.xaxis.set_major_locator(ticker.LogLocator(base=10.0, numticks=15))
ax.text(0.0, 0.1, "LogLocator(base=10, numticks=15)",
        fontsize=15, transform=ax.transAxes)

# Push the top of the top axes outside the figure because we only show the
# bottom spine.
plt.subplots_adjust(left=0.05, right=0.95, bottom=0.05, top=1.05)

plt.show()

Keywords: python, matplotlib, pylab, example, codex (see Search examples)