pylab_examples example code: spine_placement_demo.py

(Source code)

(png, hires.png, pdf)

(png, hires.png, pdf)

(png, hires.png, pdf)

(png, hires.png, pdf)

import sys
import matplotlib.pyplot as plt
import numpy as np
from matplotlib.pyplot import show

fig = plt.figure()
x = np.linspace(0,2*np.pi,100)
y = 2*np.sin(x)
ax = fig.add_subplot(1,2,1)
ax.set_title('dropped spines')
ax.plot(x,y)
for loc, spine in ax.spines.items():
    if loc in ['left','bottom']:
        spine.set_position(('outward',10)) # outward by 10 points
    elif loc in ['right','top']:
        spine.set_color('none') # don't draw spine
    else:
        raise ValueError('unknown spine location: %s'%loc)

# turn off ticks where there is no spine
ax.xaxis.set_ticks_position('bottom')
ax.yaxis.set_ticks_position('left')

ax = fig.add_subplot(1,2,2,sharex=ax)
ax.plot(x,y)
ax.set_title('normal spines')

# ----------------------------------------------------

fig = plt.figure()
x = np.linspace(-np.pi,np.pi,100)
y = 2*np.sin(x)

ax = fig.add_subplot(2,2,1)
ax.set_title('centered spines')
ax.plot(x,y)
ax.spines['left'].set_position('center')
ax.spines['right'].set_color('none')
ax.spines['bottom'].set_position('center')
ax.spines['top'].set_color('none')
ax.spines['left'].set_smart_bounds(True)
ax.spines['bottom'].set_smart_bounds(True)
ax.xaxis.set_ticks_position('bottom')
ax.yaxis.set_ticks_position('left')

ax = fig.add_subplot(2,2,2)
ax.set_title('zeroed spines')
ax.plot(x,y)
ax.spines['left'].set_position('zero')
ax.spines['right'].set_color('none')
ax.spines['bottom'].set_position('zero')
ax.spines['top'].set_color('none')
ax.spines['left'].set_smart_bounds(True)
ax.spines['bottom'].set_smart_bounds(True)
ax.xaxis.set_ticks_position('bottom')
ax.yaxis.set_ticks_position('left')

ax = fig.add_subplot(2,2,3)
ax.set_title('spines at axes (0.6, 0.1)')
ax.plot(x,y)
ax.spines['left'].set_position(('axes',0.6))
ax.spines['right'].set_color('none')
ax.spines['bottom'].set_position(('axes',0.1))
ax.spines['top'].set_color('none')
ax.spines['left'].set_smart_bounds(True)
ax.spines['bottom'].set_smart_bounds(True)
ax.xaxis.set_ticks_position('bottom')
ax.yaxis.set_ticks_position('left')

ax = fig.add_subplot(2,2,4)
ax.set_title('spines at data (1,2)')
ax.plot(x,y)
ax.spines['left'].set_position(('data',1))
ax.spines['right'].set_color('none')
ax.spines['bottom'].set_position(('data',2))
ax.spines['top'].set_color('none')
ax.spines['left'].set_smart_bounds(True)
ax.spines['bottom'].set_smart_bounds(True)
ax.xaxis.set_ticks_position('bottom')
ax.yaxis.set_ticks_position('left')
# ----------------------------------------------------

def adjust_spines(ax,spines):
    for loc, spine in ax.spines.items():
        if loc in spines:
            spine.set_position(('outward',10)) # outward by 10 points
            spine.set_smart_bounds(True)
        else:
            spine.set_color('none') # don't draw spine

    # turn off ticks where there is no spine
    if 'left' in spines:
        ax.yaxis.set_ticks_position('left')
    else:
        # no yaxis ticks
        ax.yaxis.set_ticks([])

    if 'bottom' in spines:
        ax.xaxis.set_ticks_position('bottom')
    else:
        # no xaxis ticks
        ax.xaxis.set_ticks([])

fig = plt.figure()

x = np.linspace(0,2*np.pi,100)
y = 2*np.sin(x)

ax = fig.add_subplot(2,2,1)
ax.plot(x,y)
adjust_spines(ax,['left'])

ax = fig.add_subplot(2,2,2)
ax.plot(x,y)
adjust_spines(ax,[])

ax = fig.add_subplot(2,2,3)
ax.plot(x,y)
adjust_spines(ax,['left','bottom'])

ax = fig.add_subplot(2,2,4)
ax.plot(x,y)
adjust_spines(ax,['bottom'])

# ----------------------------------------------------

fig = plt.figure()

x = np.linspace(0,2*np.pi,50)
y = np.sin(x)
y2 = y + 0.1*np.random.normal( size=x.shape )

# plot data
ax = fig.add_subplot(1,1,1)
line1,=ax.plot(x,y,'--')
line2,=ax.plot(x,y2,'bo')

# adjust the spines
adjust_spines(ax,['left','bottom'])

# set ticks and tick labels
#   x
ax.set_xlim((0,2*np.pi))
ax.set_xticks([0,np.pi,2*np.pi])
if sys.version_info[0] < 3:
    pichr = unichr(0x03C0)
else:
    pichr = chr(0x03C0)
ax.set_xticklabels(['0',pichr,'2 '+pichr])

#   y
ax.set_yticks([-1,0,1])

# disable clipping of data points by axes range
for artist in (line1,line2):
    artist.set_clip_on(False)

# adjust spine to be within ticks
ax.spines['left'].set_bounds( -1, 1 )

show()

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