Python | Matplotlib.pyplot ticks

Matplotlib is an amazing visualization library in Python for 2D plots of arrays. Matplotlib is a multi-platform data visualization library built on NumPy arrays and designed to work with the broader SciPy stack. It was introduced by John Hunter in the year 2002.

One of the greatest benefits of visualization is that it allows us visual access to huge amounts of data in easily digestible visuals. Matplotlib consists of several plots like line, bar, scatter, histogram etc.

Ticks are the values used to show specific points on the coordinate axis. It can be a number or a string. Whenever we plot a graph, the axes adjust and take the default ticks. Matplotlib’s default ticks are generally sufficient in common situations but are in no way optimal for every plot. Here, we will see how to customize these ticks as per our need.

Parameters :

Parameter	Value	Use
axis	x, y, both	Tells which axis to operate
reset	True, False	If True, set all parameters to default
direction	in, out, inout	Puts the ticks inside or outside or both
length	Float	Sets tick’s length
width	Float	Sets tick’s width
rotation	Float	Rotates ticks wrt the axis
colors	Color	Changes tick color
pad	Float	Distance in points between tick and label

Example #1: Default plot

# importing required modules 
import matplotlib.pyplot as plt 
  
# values of x and y axes 
x = [5, 10, 15, 20, 25, 30, 35, 40, 45, 50] 
y = [1, 4, 3, 2, 7, 6, 9, 8, 10, 5] 
  
plt.plot(x, y) 
plt.xlabel('x') 
plt.ylabel('y') 
  
plt.show() 

Output :

Example #2: Playing with the ticks

Suppose we don’t want to display the values of ticks or want our ticks to be tilted or want any other customization. We can do it this way.

# importing libraries 
import random 
import matplotlib.pyplot as plt 
  
fig = plt.figure() 
  
# function to get random values for graph 
def get_graphs(): 
    xs =[] 
    ys =[] 
    for i in range(10): 
        xs.append(i) 
        ys.append(random.randrange(10)) 
    return xs, ys 
  
# defining subplots 
ax1 = fig.add_subplot(221) 
ax2 = fig.add_subplot(222) 
ax3 = fig.add_subplot(223) 
ax4 = fig.add_subplot(224) 
  
# hiding the marker on axis 
x, y = get_graphs() 
ax1.plot(x, y) 
ax1.tick_params(axis ='both', which ='both', length = 0) 
  
# One can also change marker length 
# by setting (length = any float value) 
  
# hiding the ticks and markers 
x, y = get_graphs() 
ax2.plot(x, y) 
ax2.axes.get_xaxis().set_visible(False) 
ax2.axes.get_yaxis().set_visible(False) 
  
# hiding the values and displaying the marker 
x, y = get_graphs() 
ax3.plot(x, y) 
ax3.yaxis.set_major_formatter(plt.NullFormatter()) 
ax3.xaxis.set_major_formatter(plt.NullFormatter()) 
  
# tilting the ticks (usually needed when 
# the ticks are densely populated) 
x, y = get_graphs() 
ax4.plot(x, y) 
ax4.tick_params(axis ='x', rotation = 45) 
ax4.tick_params(axis ='y', rotation =-45) 
      
plt.show() 

Output:

Example #3: Changing the values of ticks.

In the first example, the x-axis and y-axis were divided by the value of 10 and 2 respectively. Let’s make it 5 and 1.

# importing libraries 
import matplotlib.pyplot as plt 
import numpy as np 
  
# values of x and y axes 
x = [5, 10, 15, 20, 25, 30, 35, 40, 45, 50] 
y = [1, 4, 3, 2, 7, 6, 9, 8, 10, 5] 
  
plt.plot(x, y, 'b') 
plt.xlabel('x') 
plt.ylabel('y') 
  
# 0 is the initial value, 51 is the final value 
# (last value is not taken) and 5 is the difference 
# of values between two consecutive ticks 
plt.xticks(np.arange(0, 51, 5)) 
plt.yticks(np.arange(0, 11, 1)) 
plt.show() 

Output:

The main difference from the 1st example is :

plt.xticks(np.arange(0, 51, 5))
plt.yticks(np.arange(0, 11, 1))

Changing the values in np.arange will change the range of ticks.

Reference: Matplotlib ticks.

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