Skip to content
Related Articles

Related Articles

Improve Article
matplotlib.pyplot.axhline() in Python
  • Last Updated : 12 Apr, 2020

Matplotlib is a library in Python and it is numerical – mathematical extension for NumPy library. Pyplot is a state-based interface to a Matplotlib module which provides a MATLAB-like interface.

matplotlib.pyplot.axhline() Function

The axhline() function in pyplot module of matplotlib library is used to add a horizontal line across the axis.

Syntax: matplotlib.pyplot.axhline(y=0, xmin=0, xmax=1, **kwargs)

Parameters: This method accept the following parameters that are described below:

  • y: This parameter is an optional and it is position in data coordinates of the horizontal line.
  • xmin: This parameter is a scalar and optional. Its default value is 0.
  • xmax: This parameter is a scalar and optional. Its default value is 1.

Returns: This returns the following:



  • line : This returns the line created by this function.
  • Below examples illustrate the matplotlib.pyplot.axhline() function in matplotlib.pyplot:

    Example #1:




    # Implementation of matplotlib.pyplot.annotate() function
      
    import numpy as np
    import matplotlib.pyplot as plt
      
    t = np.linspace(-10, 10, 100)
    sig = 1 / t
      
    plt.axhline(y = 0, color ="green", linestyle ="--")
    plt.axhline(y = 0.5, color ="green", linestyle =":")
    plt.axhline(y = 1.0, color ="green", linestyle ="--")
      
    plt.axvline(color ="black")
      
    plt.plot(t, sig, linewidth = 2
             label = r"$\sigma(t) = \frac{1}{x}$")
      
    plt.xlim(-10, 10)
    plt.xlabel("t")
    plt.title("Graph of 1 / x")
    plt.legend(fontsize = 14)
      
    plt.show()

    Output:

    Example #2:




    # Implementation of matplotlib.pyplot.annotate() 
    # function
      
    import numpy as np
    import matplotlib.pyplot as plt
      
    x = np.linspace(0, 13, 100)
      
    plt.rcParams['lines.linewidth'] = 2
    plt.figure()
      
    plt.plot(x, np.sin(x), label ='Line1'
             color ='green', linestyle ="--")
      
    plt.plot(x, np.sin(x + 0.5), label ='Line2',
             color ='black', linestyle =":")
      
    plt.axhline(0, label ='Line3', color ='black')
      
      
    plt.title('Axhline() Example')
    l = plt.legend(loc ='upper right')
      
    # legend between blue and orange 
    # line
    l.set_zorder(2.5)
      
    plt.show()

    Output:

     Attention geek! Strengthen your foundations with the Python Programming Foundation Course and learn the basics.  

    To begin with, your interview preparations Enhance your Data Structures concepts with the Python DS Course. And to begin with your Machine Learning Journey, join the Machine Learning – Basic Level Course




    My Personal Notes arrow_drop_up
    Recommended Articles
    Page :