import numpy as np
import matplotlib.pyplot as plt

def oppg1():
    with open('data12.txt', 'r') as file:
        lines = [[float(x) for x in line.split()] for line in file.readlines()]
        data = np.transpose(np.array(lines))

    x_data = data[1]
    y_data = data[2]

    plt.scatter(x_data,y_data)
    plt.show()
    coeff = np.polyfit(x_data,y_data,1)

    print(coeff)
    print(np.polyval(coeff,6000))

def oppg2():
    x_data = np.array([51, 52, 53, 54, 55])
    y_data = np.array([51.32, 48.71, 47.68, 46.52, 47.26])

    coeff = np.polyfit(x_data, y_data, 1)

    reg = np.poly1d(coeff)

    print(1-sum((y_data-reg(x_data))**2)/sum((y_data-np.mean(y_data))**2))

oppg2()