How to Add Labels in a Plot using Python?
Prerequisites: Python Matplotlib
In this article, we will discuss adding labels to the plot using Matplotlib in Python. But first, understand what are labels in a plot. The heading or sub-heading written at the vertical axis (say Y-axis) and the horizontal axis(say X-axis) improves the quality of understanding of plotted stats.
Example: Let’s create a simple plot
Python
# python program to plot graph without labelsimport matplotlibimport matplotlib.pyplot as pltimport numpy as np# it will take x coordinates by default # starting from 0,1,2,3,4...y = np.array([3, 8, 1, 10])plt.plot(y)plt.show() |
Output:
Plot without Labels or Title
Creating Labels for a Plot
By using pyplot() function of library we can add xlabel() and ylabel() to set x and y labels.
Example: Let’s add Label in the above Plot
Python
# python program for plots with labelimport matplotlibimport matplotlib.pyplot as pltimport numpy as np# Number of children it was default in earlier casex = np.array([0, 1, 2, 3])# Number of familiesy = np.array([3, 8, 1, 10])plt.plot(x, y)# Label for x-axisplt.xlabel("Number of Childrens")# Label for y-axisplt.ylabel("Number of Families")plt.show() # for display |
Output:
Plot with Labels
If you would like to make it more understandable, add a Title to the plot, by just adding a single line of code.
plt.title("Survey Of Colony")
Example:
Python3
# python program for plots with labelimport matplotlibimport matplotlib.pyplot as pltimport numpy as np# Number of children it was default in earlier casex = np.array([0, 1, 2, 3])# Number of familiesy = np.array([3, 8, 1, 10])plt.plot(x, y)# Label for x-axisplt.xlabel("Number of Childrens")# Label for y-axisplt.ylabel("Number of Families")# title of the plotplt.title("Survey Of Colony")plt.show() # for display |
Output:
Plot with Title
Set Font Properties for Titles and Labels
In order to make the Plot more attractive use the fontdict parameter in xlabel(), ylabel(), and title() to apply the font properties.
Python
# Adding font properties to labels and titlesimport matplotlibimport matplotlib.pyplot as pltimport numpy as np# Number of Childrenx = np.array([0, 1, 2, 3])# Number of Familiesy = np.array([3, 8, 1, 10])# label including this form1 will have these propertiesform1 = {'family': 'serif', 'color': 'blue', 'size': 20}# label including this form2 will have these propertiesform2 = {'family': 'serif', 'color': 'darkred', 'size': 15}plt.plot(x, y)plt.xlabel("Number of Childrens", fontdict=form1)plt.ylabel("Number of Families", fontdict=form1)plt.title("Survey Of Colony", fontdict=form2)plt.show() |
Output:
Plot with Font Properties
