Mark different color points on matplotlib

Last Updated : 03 Jun, 2020

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.

In this article, the task is to mark different color points in a graph based on a condition that the values of the elements of the list say x is less than or equal to 7 should be colored in blue and those greater should be colored magenta. The idea is to plot a graph having points grouped under one condition in different colors, basically to group the clusters in one color. For this, we run a loop for all values of x and assign a color value to the corresponding value of x. A list will be made of blue and magenta colors specifying the color at the ith index.

Below is the implementation.

import  numpy as np 
import matplotlib.pyplot as plt 
  
  
# values of x 
x = np.array([1, 2, 3, 4, 5, 
              6, 7, 8, 9, 10]) 
  
# values of y 
y = np.array([10, 9, 8, 7, 6, 5, 
              4, 3, 2, 1]) 
  
# empty list, will hold color value 
# corresponding to x 
col =[] 
  
for i in range(0, len(x)): 
    if x[i]<7: 
        col.append('blue')   
    else: 
        col.append('magenta')  
  
for i in range(len(x)): 
      
    # plotting the corresponding x with y  
    # and respective color 
    plt.scatter(x[i], y[i], c = col[i], s = 10, 
                linewidth = 0) 
      
  
plt.show() 