%n1 = 21; A = gallery('moler',n1);  b1 = A*ones(n1,1);
%tol = 1e-6;  maxit = 15;  M = diag([10:-1:1 1 1:10]);
%[x1,flag1,rr1,iter1,rv1] = pcg(A,b1,tol,maxit,M);

%n = 3;
%A = gallery('poisson', n);
%b = ones(n^2, 1);
%pcg(A, b)
%A \ b
%gauss_elimination(A, b)

%D = diag(diag(A)); 
%E = tril(-A, -1);
% Jacobi
%split(D, A, b, n)
% Gauss-Seidel
%split(D-E, A, b, n)

%n1 = 21; A = gallery('moler',n1);  b1 = A*ones(n1,1);
%tol = 1e-6;  maxit = 15;  M = diag([10:-1V:1 1 1:10]);
%[x1,flag1,rr1,iter1,rv1] = pcg(A,b1,tol,maxit,M);
% x1, rv1: vectors
% flag1, rr1, iter1: scalars

%[A, b] = getproblem(1);
%x1 = mypcg(A, b);

myeval([1, 2, 3, 4, 5], 'foo')
