function [c,ceq,gradc,gradceq] = twocone(x)
% This constraint is two cones, z > -10 + r
% and z < 3 - r
%
ceq = [];

r = sqrt(x(1)^2 + x(2)^2);

c = [-10+r-x(3);
    x(3)-3+r];

if nargout > 2
    
    gradceq = [];
    
    gradc = [x(1)/r,x(1)/r;
    x(2)/r,x(2)/r;
    -1,1];

end
