sylvester3a

 solves iteratively ax+bxc=d

0001 % solves iteratively ax+bxc=d
0002 
0003 function x=sylvester3a(x0,a,b,c,d)
0004   a_1 = inv(a);
0005   b = a_1*b;
0006   d = a_1*d;
0007   e = 1;
0008   iter = 1;
0009   while e > 1e-8 & iter < 500
0010     x = d-b*x0*c;
0011     e = max(max(abs(x-x0)));
0012     x0 = x;
0013     iter = iter + 1;
0014   end
0015   if iter == 500
0016     warning('sylvester3a : Only accuracy of %10.8f is achieved after 500 iterations') 
0017   end