import numpy	# modul pro matematické funkce a práci s poli
import matplotlib.pyplot as plt

lines = numpy.loadtxt("cv11/upf_cv11_linear.txt")	# nacti soubor do pole N x 3

x = lines[:,0]
y = lines[:,1]
sigma = lines[:,2]

plt.errorbar(x,y,sigma,marker='o',ls='None')

############ fitovani polynomu: #########################################
invSigma = 1.0 / sigma
M=2	# pocet parametru
p = numpy.polyfit(x, y, deg=(M-1), w=invSigma, cov=True)

print("Koeficienty (od nejvyssi mocniny x):")
print(p[0])

yModel = numpy.polyval(p[0], x)
plt.plot(x,yModel)

print("\nMatice kovariance:")
print(p[1]);

string = ""
for i in range(0,M):
	string = string + " " + str(round(numpy.sqrt(p[1][i][i]),3))
print("\nSigmas: " + string)

plt.show()