How to force Matplotlib to show the values on X-axis as integers?

By default, Matplotlib may display decimal values on the X-axis when plotting data. To force the X-axis to show only integer values, you can use plt.xticks() with a range of integers or set a custom tick locator.

Method 1: Using plt.xticks() with range()

Create a range of integers based on your data's minimum and maximum values ?

import math
import matplotlib.pyplot as plt

# Sample data
x = [1.0, 1.75, 2.90, 3.15, 4.50, 5.50]
y = [0.17, 1.17, 2.98, 3.15, 4.11, 5.151]

plt.figure(figsize=(8, 5))
plt.plot(x, y, marker='o')

# Force integer ticks on X-axis
integer_ticks = range(math.floor(min(x)), math.ceil(max(x)) + 1)
plt.xticks(integer_ticks)

plt.xlabel("X-axis")
plt.ylabel("Y-axis")
plt.title("Integer Values Only on X-axis")
plt.grid(True, alpha=0.3)
plt.show()

# Displays a plot with X-axis showing only integers: 1, 2, 3, 4, 5, 6

Method 2: Using MultipleLocator

For more control, use MultipleLocator from matplotlib.ticker ?

import matplotlib.pyplot as plt
from matplotlib.ticker import MultipleLocator

# Sample data
x = [0.5, 1.2, 2.8, 3.9, 5.1, 6.7]
y = [1, 4, 2, 8, 3, 6]

plt.figure(figsize=(8, 5))
plt.plot(x, y, 'b-o', linewidth=2, markersize=6)

# Set major ticks to appear at integer intervals
plt.gca().xaxis.set_major_locator(MultipleLocator(1))

plt.xlabel("X-axis")
plt.ylabel("Y-axis")
plt.title("Using MultipleLocator for Integer Ticks")
plt.grid(True, alpha=0.3)
plt.show()

# Displays a plot with X-axis ticks at every integer value

Method 3: Custom Integer Range

Manually specify the exact integer values you want to display ?

import matplotlib.pyplot as plt

# Sample data
categories = [1.1, 2.3, 3.7, 4.2, 5.8]
values = [10, 25, 15, 30, 20]

plt.figure(figsize=(8, 5))
plt.bar(categories, values, alpha=0.7, color='skyblue')

# Set custom integer ticks
custom_ticks = [1, 2, 3, 4, 5, 6]
plt.xticks(custom_ticks)

plt.xlabel("Categories")
plt.ylabel("Values")
plt.title("Bar Chart with Integer X-axis")
plt.show()

# Displays a bar chart with X-axis showing integers 1, 2, 3, 4, 5, 6

Comparison

Conclusion

Use plt.xticks(range()) for simple cases or MultipleLocator(1) for more advanced control. Both methods ensure your X-axis displays clean integer values instead of decimals.