Start your axis at zero

In [1]:

from matplotlib import pyplot as plt
import seaborn as sns
import numpy as np

# Aesthetics
sns.set_style('ticks')
plt.rcParams["font.family"] = "serif" # use Serif style as default font

In [2]:

# Create simple data
x = ["Marco", "Tereza", "Robert"]
y = [70, 60, 99] # millions of inhabitants

In [3]:

fig, axes = plt.subplots(1,2, figsize=(10,4))
axes[0].bar(x,y)
axes[1].bar(x,y)

axes[0].set_ylim(50,100)
axes[0].set_title('Truncated axis')
axes[1].set_title('Complete axis')

for ax in axes:
    ax.set_ylabel("Student Grades [$\%$ scale]")
    ax.grid()

fig.savefig('../figures/truncated-bars.pdf', bbox_inches='tight')
plt.show()

Figure 1: Comparing barplots with truncated or complete Y-axis.

In [4]:

fig, axes = plt.subplots(1,2, figsize=(12,4))

np.random.seed(4)

quarters = ['Q' + str(index) for index in range(1, 5)]
for student in x:
    grades = np.linspace(70,90, 4) + np.random.normal(0, 5, 4)
    axes[0].plot(quarters, grades, label=student)
    axes[1].plot(quarters, grades, label=student)

axes[1].legend()
axes[1].set_ylim(0,100)
axes[0].set_title('Truncated axis')
axes[1].set_title('Complete axis')
for ax in axes:
    ax.set_ylabel("Student Grades [$\%$ scale]")
    ax.grid()
fig.savefig('../figures/truncated-lines.pdf', bbox_inches='tight')
plt.show()

Figure 2: Comparing lineplots with truncated or complete Y-axis.

Figure 1: Comparing barplots with truncated or complete Y-axis. Figure 2: Comparing lineplots with truncated or complete Y-axis.