rand('state',333);
imax = 300; n = 60; tol=1e-14;

current = 2*rand(n,4) - 1;
children = zeros(n,4);
vals = zeros(n,1);
for j=1:n
    vals(j) = maxerror(current(j,:));
end
oldbest = min(vals);
for i=1:imax
    for j=1:n
        select = ceil(n*rand(3,1));
        children(j,:) = [1 0.4 -0.4]*current(select,:);
    end
    for j=1:n
        childval = maxerror(children(j,:));
        if childval < vals(j)
            current(j,:) = children(j,:);
            vals(j) = childval;
        end
    end
    if mod(i,10)==0
        best = min(vals);
        if (abs(best-oldbest) < tol), break; end
        oldbest = best;
    end
end
sol = min(vals)