import matplotlib.pyplot as plt
import numpy as np

#x = [146.66, 293.33, 439.99, 573.33, 693.33, 773.33, 839.99, 879.99]
x = [0.3, 0.4, 0.5, 0.6, 0.8, 1.0] 

#y = [-37, -79, -122, -161, -194, -218, -234, -245]
#y=[-53, -110, -165, -214, -261, -292, -314, -327]
#y = [-67, -137, -209, -274, -328, -368, -395, -411]
#y = [-83, -166, -249, -327, -393, -441, -474, -496]
#y = [-113, -229, -336, -442, -531, -595, -638, -664]
#y = [-142, -286, -424, -553, -663, -745, -800, -831]
#y=[135, 277, 417, 547, 660, 736,  791, 821]
y = [-0.28, -0.38, -0.47, -0.56, -0.75, -0.94]
u0 = 0

if len(x) != len(y):
    print("size mismatch")
    exit()

y = [i - u0 for i in y]

n = len(x)

mean_xy = 0
mean_x_sq = 0

for i in range(n):
    mean_xy += x[i] * y[i]
    mean_x_sq += x[i] ** 2

mean_xy /= n
mean_x_sq /= n

k = mean_xy / mean_x_sq

print("k = ", k)

plt.scatter(x,y)
#plt.show()
x_axis = np.array(range(0, 1000))
y_axis = k * x_axis 

plt.plot(x_axis, y_axis)
plt.show()
#`plot(x, y))