Align y-labels

Two methods are shown here, one using a short call to Figure.align_ylabels and the second a manual way to align the labels.

import numpy as np
import matplotlib.pyplot as plt


def make_plot(axs):
    box = dict(facecolor='yellow', pad=5, alpha=0.2)

    # Fixing random state for reproducibility
    np.random.seed(19680801)
    ax1 = axs[0, 0]
    ax1.plot(2000*np.random.rand(10))
    ax1.set_title('ylabels not aligned')
    ax1.set_ylabel('misaligned 1', bbox=box)
    ax1.set_ylim(0, 2000)

    ax3 = axs[1, 0]
    ax3.set_ylabel('misaligned 2', bbox=box)
    ax3.plot(np.random.rand(10))

    ax2 = axs[0, 1]
    ax2.set_title('ylabels aligned')
    ax2.plot(2000*np.random.rand(10))
    ax2.set_ylabel('aligned 1', bbox=box)
    ax2.set_ylim(0, 2000)

    ax4 = axs[1, 1]
    ax4.plot(np.random.rand(10))
    ax4.set_ylabel('aligned 2', bbox=box)


# Plot 1:
fig, axs = plt.subplots(2, 2)
fig.subplots_adjust(left=0.2, wspace=0.6)
make_plot(axs)

# just align the last column of axes:
fig.align_ylabels(axs[:, 1])
plt.show()

See also

Figure.align_ylabels and Figure.align_labels for a direct method of doing the same thing. Also Aligning Labels

Or we can manually align the axis labels between subplots manually using the set_label_coords method of the y-axis object. Note this requires we know a good offset value which is hardcoded.

fig, axs = plt.subplots(2, 2)
fig.subplots_adjust(left=0.2, wspace=0.6)

make_plot(axs)

labelx = -0.3  # axes coords

for j in range(2):
    axs[j, 1].yaxis.set_label_coords(labelx, 0.5)

plt.show()

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References

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

import matplotlib
matplotlib.figure.Figure.align_ylabels
matplotlib.axis.Axis.set_label_coords
matplotlib.axes.Axes.plot
matplotlib.pyplot.plot
matplotlib.axes.Axes.set_title
matplotlib.axes.Axes.set_ylabel
matplotlib.axes.Axes.set_ylim