Scikit-learn LinearRegression vs Numpy Polyfit

polyfit.py

fx = np.linspace(min(x), max(x), 100) # x-axis data points
f1 = np.polyfit(x, y, 1)
f2 = np.polyfit(x, y, 2)
f3 = np.polyfit(x, y, 3)
f4 = np.polyfit(x, y, 4)

for coefs in [f1, f2, f3, f4]:
    f = np.poly1d(coefs)
    print('Coefficients: {}'.format(coefs[:-1]))
    print('Intercept: {}'.format(coefs[-1]))
    print('Error: {}'.format(error(f, x, y)))

    fitted_curve = np.poly1d(coefs)(fx)
    plt.scatter(x, y, label="observed")
    plt.plot(fx, fitted_curve, c="red", label="fitted")
    plt.grid()
    plt.legend()
    plt.show()