Not sure why I get this error: Error using SerialLink/fkine (line 84) q must have 4 columns Error in fedr (line 36) T = robo.fkine(qn);

%%I should get a value of less than 2 when running the program

function err = dhobjective1 (para)
    %initial error is zero
    
    
    robo = [0 0 0 0]; %robot to pass new parameters
    
    %disturbing the parameters
    d1 = 0;
    a1 = 7.5;
    a2 = 3.0;
    d2 = 10;
    d4 = 0.7;
    a4 = 1;
    para = [d1 a1 d2 a2 d4 a4];
    
    L(1) = Link([pi/2 para(2) para(1) 0]);
    %L1.qlim = [0, pi];
    L(2) = Link([pi/2 para(4) para(3) 0]);
    %L2.qlim = [0, pi];
    L(3) = Link([0 0 0 -pi/2]);
    %L3.qlim = [0, pi];
    %L(4) is the end effector where the pen attaches
    L(4) = Link([10 para(5) para(1) 10]);
    %L4.qlim = [0, pi];
    robo = SerialLink(L, 'name', 'robo');
    data = [0 180 8; 0 135 14.5; 45 135 14.5;...
            45 180 8.5; 90 180 8.5];
%     robo.base = [0 2 0 0];
    %open file of precompute values
    
    err = 0;
    for i = 1:5 
        
        qn = data(i,1:2);
        dist = data(i, 3);
        T = robo.fkine(qn);
        Ndist = sqrt((T.t(1).^2) + (T.t(2).^2) + (T.t(3).^2));
        %compute error
        Eerr = abs(dist - Ndist);
        err = err + Eerr; 
    end
    err = err/5;
end

[程]

met too

did u find someway to solve?