Scatter a 2D numpy array in matplotlib

Question

I have a 4x4 data array like

data = np.array([[0,1,1,1], [1,0,0,1], [1,1,1,0], [0,0,0,1]])

Now I want to scatter this array on a 2D plot.

If data[i,j] is equal to 1, there should be a colored spot at point (x,y)=(i,j). I've tried with scatter plot in matplotlib, but somehow couldn't make it work.

Answer 1

You can do it with

import numpy as np
import matplotlib.pyplot as plt

data = np.array([[0,1,1,1], [1,0,0,1], [1,1,1,0], [0,0,0,1]])

# get the indices where data is 1
x,y = np.argwhere(data == 1).T

plt.scatter(x,y)
plt.show()

However, when you just want to visualize the 4x4 array you can use matshow

plt.matshow(data)
plt.show()