clear all
close all
clc

ub = 220+0.2i;
y12 =inv(2+3i);
y14 = inv(2+3i);
y23 = inv(3+3i);
y34 = inv(3+3i);
i2 = -0.6+0.4i;
i3 = -0.6+0.8i;
i4 = -1.2+0.2i;

y=[y12+y14 -y12 0 -y14
  -y12 y12+y23 -y23 0
  0 -y23 y23+y34 -y34
  -y14 0 -y34 y14+y34]

y21 = y(2,1);
y22 = y(2,2);
y23 = y(2,3);
y24 = y(2,4);
y31 = y(3,1);
y32 = y(3,2);
y33 = y(3,3);
y34 = y(3,4);
y41 = y(4,1);
y42 = y(4,2);
y43 = y(4,3);
y44 = y(4,4);
  
u2i0 = 210; %tipovana hodnota napatia v uzle
u3i0 = 210;
u4i0 = 210;
iteracia = 1
u2 = inv(y22)*(i2-y21*ub-y23*u3i0-y24*u4i0)
u3 = inv(y33)*(i3-y31*ub-y34*u4i0-y32*u2i0)
u4 = inv(y44)*(i4-y41*ub-y42*u2i0-y43*u3i0)
u2-u2i0
ep2 = ans;
u3-u3i0
ep3 = ans;
u4-u4i0
ep4 = ans;
u2i0 = u2;
u3i0 = u3;
u4i0 = u4;
epsilon = 0.01 %presnost
while(ep2>epsilon)||(ep3>epsilon)||(ep4>epsilon)
iteracia = ++iteracia
u2 = inv(y22)*(i2-y21*ub-y23*u3i0-y24*u4i0)
u3 = inv(y33)*(i3-y31*ub-y34*u4i0-y32*u2i0)
u4 = inv(y44)*(i4-y41*ub-y42*u2i0-y43*u3i0)
u2-u2i0
ep2 = ans;
u3-u3i0
ep3 = ans;
u4-u4i0
ep4 = ans;
u2i0 = u2;
u3i0 = u3;
u4i0 = u4;

end