import pyfits
import numpy

# nacteni snimku
barn = pyfits.open('barnard_y_0007.fits')
cts = barn[0].data
barn.close()

# pozadi
pozadi = cts[1100-10:1100+10,840-10:840+10]
back = pozadi.mean()
print("Pozadi=",back)

# detail hvezdy
box = 4
x0 = 863
y0 = 957
detail = cts[y0-box:y0+box,x0-box:x0+box]
print(detail)

# wahy
detail = detail - int(back)
print(detail)

#teziste
s = 0
n = 0
for i in range(0,2*box):
  for j in range(0,2*box):
     s = s + detail[j,i]*i
     n = n + detail[j,i]
xt = s / n
print("Teziste v x:",xt)

s = 0
n = 0
for i in range(0,2*box):
  for j in range(0,2*box):
     s = s + detail[j,i]*j
     n = n + detail[j,i]
yt = s / n
print("Teziste v y =",yt)