Centered Text Issue

centered_text_issue.py

#!/usr/bin/env python
import matplotlib as mpl
import matplotlib.pyplot as plt
from mpl_toolkits.axes_grid1 import axes_divider as divider
from mpl_toolkits.axes_grid1.anchored_artists import AnchoredText


def add_center_text(ax):
    pos = ax.get_position().bounds
    l, b, w, h = pos
    w2 = 0.5
    l2 = l + 0.5*w - w2/2.
    b2 = b+0.8575*h
    h2 = 0.1*h
    ax2 = plt.axes([l2, b2, w2, h2], xticks=[], yticks=[], frameon=False)
    ax2.text(0.5, 0.5, "Centered Title", ha='center', va='center', fontsize=18,
        bbox=dict(boxstyle='round, pad=0.5, rounding_size=0.25', fc="white",
        ec="k", lw=2))
    plt.axes(ax)

def add_center_text_alt(locator, ax):
    pos = locator.get_position_runtime(ax, mpl.get_backend())
    l, b, w, h = pos
    w2 = 0.5
    l2 = l + 0.5*w - w2/2.
    b2 = b+0.8575*h
    h2 = 0.1*h
    ax2 = plt.axes([l2, b2, w2, h2], xticks=[], yticks=[], frameon=False)
    ax2.text(0.5, 0.5, "Centered Title", ha='center', va='center', fontsize=18,
        bbox=dict(boxstyle='round, pad=0.5, rounding_size=0.25', fc="white",
        ec="k", lw=2))
    plt.axes(ax)

def add_center_text_alt2(ax, fsize=10):
    title = 'Hello World\nToday'
    at = AnchoredText(title, prop=dict(size=fsize, ha='left'),
        frameon=True,  loc=9, borderpad=0.75)
    at.patch.set_boxstyle("round, pad=0.2, rounding_size=0.25")
    ax.add_artist(at)

    at = AnchoredText(title, prop=dict(size=fsize, ha='center'),
        frameon=True,  loc=9, borderpad=5)
    at.patch.set_boxstyle("round, pad=0.2, rounding_size=0.25")
    ax.add_artist(at)

    at = AnchoredText(title, prop=dict(size=fsize, ha='right'),
        frameon=True,  loc=9, borderpad=9)
    at.patch.set_boxstyle("round, pad=0.2, rounding_size=0.25")
    ax.add_artist(at)


fig = plt.figure(figsize=(8,12))
ax1 = fig.add_subplot(311)
locator = divider.make_axes_locatable(ax1)
cax1 = locator.append_axes("right", size="5%", pad="3%")
plt.draw()
add_center_text(ax1)
ax1.grid()


ax2 = fig.add_subplot(312)
locator = divider.make_axes_locatable(ax2)
cax2 = locator.append_axes("right", size="5%", pad="3%")
plt.draw()
add_center_text_alt(locator, ax2)
ax2.grid()


ax3 = fig.add_subplot(313)
locator = divider.make_axes_locatable(ax3)
cax3 = locator.append_axes("right", size="5%", pad="3%")
plt.draw()
add_center_text_alt2(ax3)
ax3.grid()
plt.show()