How to get equation or value on matplotlib plot

Question

i want to get equation or value on matplotlib plot

i make plot x: range(5), y = [ 5, 20, 1, 7,9 ]

matplotlib make plot like under the picture.

And then, i want to get value that is between 20 and 1

I guess matplotlib fit anything model, and make y_hat and plotting y_hats

so, who are teach me, how to get eqation or access equation or value

-- if you don't understand my text, reference the picture. i think, you will understand what i want to do.

Answer 1

It will be very easy to use the NumPy interp function. Just giving the x-positions and original X,Y array. np.interp will return the corresponding y-values (Linear interpolation).

import numpy as np
import matplotlib.pyplot as plt
x = range(5)
y =  [ 5 , 20 , 1 , 7 ,9 ]

xvals = np.linspace(1, 2, 10)
yinterp = np.interp(xvals, x, y)
plt.plot(x, y, '-o',label="org data")

plt.plot(xvals, yinterp, 'x',label="interp data")
plt.legend()
plt.savefig("interp.png")
plt.show()