Plotting two random numpy array

If you have a look at the shapes of a and b, you'll find they both have a shape of (1, 10).

a = np.random.randint(2, 10, size=(1, 10))
b = np.random.randint(5, 15, size=(1, 10))
print(a.shape)
print(b.shape)

Matplotlib sees this as many "lines", each "line" with just one point! What you want is a single line with 10 points, so a and b should have a shape of (10,) instead.

The following code the above issue:

import numpy as np
import matplotlib.pyplot as plt

# Decalring numpy array variable
a = np.random.randint(2, 10, 10)
b = np.random.randint(5, 15, 10)

# plotting
plt.title("Line graph")
plt.xlabel("X axis")
plt.ylabel("Y axis")
plt.plot(a, b, color ="green", label="Sample Line", marker="*")
plt.show()

But the result is as follows:

Here we have plotted a as the coordinates of points on the x-axis, and b as the coordinates of the line on the y-axis. Perhaps you wanted two lines that are continuous along the x-axis? If so, the following code will solve this:

import numpy as np
import matplotlib.pyplot as plt

# Decalring numpy array variable
a = np.random.randint(2, 10, 10)
b = np.random.randint(5, 15, 10)
xAxis = np.arange(10)

# plotting
plt.title("Line graph")
plt.xlabel("X axis")
plt.ylabel("Y axis")
plt.plot(xAxis, a, color ="red", label="Sample Line", marker="*")
plt.plot(xAxis, b, color ="blue", label="Sample Line", marker="*")
plt.show()