function [A, iterJ, iterG, x1, x2] = pg162_text
  n=10;
  A=3*eye(n) - 2*diag(ones(n-1,1),1) - diag(ones(n-1,1),-1);
  b=A*ones(n,1);
  x0=zeros(n,1);
  [x1,iterJ]=itermeth(A,b,x0,400,1.e-12,'J');
  [x2,iterG]=itermeth(A,b,x0,400,1.e-12,'G');
end