import numpy as np
import matplotlib.pyplot as plt
import scipy.optimize as opt

#prvi zadatak
Z,D1,D2 = np.loadtxt('rm-python_2.004.txt', delimiter = ' ', unpacked = True)
plt.plot(Z,D1,'g+')
plt.plot(Z,D2,'r+')

#drugi zadatak
x1 = np.linspace(0,50,100)
r1 = np.poly1d(np.polyfit(Z,D1,3))
plt.plot(x1, r1(x1), 'g')

#treci zadatak
x2 = np.linspace(min(Z), max(Z), 100)
r2 = interp1d(Z,D2,kind = 'cubic')
plt.plot(x2,r2(x2))

#cetvrti zadatak
def f(x):
    return r1(x) - r2(x)

n = fsolve(f, [10,30])
plt.scatter(n, r1(n))

#peti zadatak
x = np.linspace(n[0], n[1], 100)
p1 = abs(np.trapz(r1(x),x,dx = 0.001))
p2 = abs(np.trapz(r2(x),x,dx = 0.001))
print('Povrsina: ' , p2-p1)
plt.fill_between(x,r1(x),r2(x),color = 'lightblue')

plt.show()