0

I have the following code:

import matplotlib.pyplot as plt
import numpy as np
a=np.array([[0],[1],[2]], np.int32)
b=np.array([[3],[4],[5]], np.int32)

plt.plot(a, color = 'red', label = 'Historical data')
plt.plot(b, color = 'blue', label='Predicted data')
plt.legend()
plt.show()

That gives me a graph of 2 lines each starting from x-axis = 0.

How can I concatenate 'a' and 'b' and plot the graph such that 'b' continues on the x-axis where 'a' ended?

Thanks!

1 Answer 1

2

You can add an x array and then increase its value in the next plot so it will get appended to the previous plot.

import matplotlib.pyplot as plt
import numpy as np
a=np.array([[0],[1],[2]], np.int32)
b=np.array([[3],[4],[5]], np.int32)
x = np.arange(a.shape[0])

plt.plot(x, a, color = 'red', label = 'Historical data')
plt.plot(x+a.shape[0], b, color = 'blue', label='Predicted data')
plt.legend()
plt.show()
Sign up to request clarification or add additional context in comments.

2 Comments

Follow up question: What if the numpy arrays are: a=np.array([[0],[1],[2]], np.int32) b=np.array([[2],[3],[4],[5]], np.int32) ? I get this error: ValueError: x and y must have same first dimension, but have shapes (3,) and (4, 1) How can i get around this?
Since the shape of a and b are different here you'll have to make two different x variable x1 = np.arange(a.shape[0]) and x2 = np.arange(a.shape[0], a.shape[0]+b.shape[0]). x1 can be used with a and x2 can be used with b

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.