reducer_warmup.m

function reducer_warmup( options )
N = 8;
G = gallery('tridiag', N, -1, 2, -1);
G(1,1) = 1;
G(N,N) = 1;
is_ext_node = [1 zeros(1, N-2) 1]';
reducer(G, is_ext_node, options);
end