import numpy as np
import matplotlib.pyplot as plt

`polyfit`

Objective is to create a fit of a set of data points and plot it.

1 degree polynomial

x = np.array([1, 2, 3, 4])
y = np.array([1, 2, 3, 4])

fit = np.polyfit(x, y, 1)

equation = np.poly1d(fit)

x_points = np.linspace(1, 10, 100)
y_points = equation(x_points)

plt.figure(figsize=(4, 2))
plt.plot(x, y, '.')
plt.plot(x_points, y_points, '-r')

[<matplotlib.lines.Line2D at 0x14c8564d0>]

png

degree_2_fit = np.polyfit(x, y, 2)

degree_2_eq = np.poly1d(degree_2_fit)

print(degree_2_eq)

            2
-4.958e-16 x + 1 x - 2.442e-15

y_points = degree_2_eq(x_points)

plt.figure(figsize=(4, 2))
plt.plot(x, y, '.', x_points, y_points, '-r')

[<matplotlib.lines.Line2D at 0x14c7af670>,
 <matplotlib.lines.Line2D at 0x14c7afcd0>]

png