Size mismatch when i am using simulink

Greetings all, i am currently using simulink to do a project, however when i run the model i get this errors

1.Simulink does not have enough information to determine output sizes for this block. If you think the errors below are inaccurate, try specifying types for the block inputs and/or sizes for the block outputs.

Component:MATLAB Function | Category:Coder error

2.Size mismatch (size [1 x 3] ~= size [3 x 3]). The size to the left is the size of the left-hand side of the assignment. More informationFunction 'MATLAB Function1' (#81.979.988), line 52, column 1: "param_vec" Launch diagnostic report.

Component:MATLAB Function | Category:Coder error

3.Function call failed. Function 'MATLAB Function1' (#81.79.119), line 12, column 5: "compute_inv(x, y ,z, l1, l2,l3, epsilon)" Launch diagnostic report.

Component:MATLAB Function | Category:Coder error

4.Errors occurred during parsing of 'Robot_Arm/MATLAB Function1'.

Component:MATLAB Function | Category:Coder error

5.Simulink cannot determine sizes and/or types of the outputs for block 'Robot_Arm/MATLAB Function1' due to errors in the block body, or limitations of the underlying analysis. The errors might be inaccurate. Fix the indicated errors, or explicitly specify sizes and/or types for all block outputs.

Component:MATLAB Function | Category:Coder error

6.Simulink cannot determine sizes and/or types of the outputs for block 'Robot_Arm/MATLAB Function1' due to errors in the block body, or limitations of the underlying analysis. The errors might be inaccurate. Fix the indicated errors, or explicitly specify sizes and/or types for all block outputs.

Component:Simulink | Category:Model error

7.Error in port widths or dimensions. 'Output Port 1' of 'Robot_Arm/MATLAB Function1/z' is a one dimensional vector with 1 elements.

function [t1,t2,t3] = fcn(x,y,z)



l1=0.1;
l2= 0.1;
l3=0.045;
epsilon = 0.001;
t = compute_inv(x, y ,z, l1, l2,l3, epsilon) ;


t1=t(1);
t2=t(2);
t3=t(3);

end
function f =roots_fn_inv(x,y,z,t1,t2,t3,l1,l2,l3);
f = [l1*cos(t1)*(cos(t2+t3)+cos(t2))-x;
    l2*sin(t1)*(cos(t2+t3)+cos(t2))-y;
    l1*sin(t2+t3)+l1*sin(t2)+l3-z;];
end



function f_dash = drev_roots_fn_inv(t1,t2,t3,l1,l2,l3);
f_dash = [-(sin(t1)*(cos(t2+t3)+cos(t2)))/10 -(cos(t1)*(sin(t2 + t3)+sin(t2)))/10 -(sin(t2 + t3)*cos(t1))/10;
           (cos(t1)*(cos(t2+t3)+cos(t2)))/10 -(sin(t1)*(sin(t2 + t3)+sin(t2)))/10 -(sin(t2 + t3)*sin(t1))/10;
           0 cos(t2+t3)/10+cos(t2)/10 cos(t2+t3)/10;]
end

function param_vec = compute_inv (x, y, z, l1, l2 ,l3, epsilon);

t1=pi/2;
t2=pi/2;
t3=pi/2;
readings_t1=t1;
readings_t2=t2;
readings_t3=t3;

param_vec=[t1,t2,t3];
F_n=roots_fn_inv(x,y,z,t1,t2,t3,l1,l2,l3);

n=1;
while norm(F_n) > epsilon

F_n_dash=drev_roots_fn_inv(t1, t2,t3,l1,l2,l3) ;


param_vec = param_vec - F_n_dash\F_n;


t1=param_vec(1) ;
t2=param_vec (2);
t3=param_vec (3);

F_n = roots_fn_inv(x,y,z,t1,t2,t3,l1,l2,l3);

n= n+1;



end
end

Answer 1

[Sam Chak]

Hi @alaa

You need to perform a transpose on the param_vec vector as indicated in the code.

x            = 0.1;
y            = x;
z            = y;
[t1, t2, t3] = fcn(x, y, z)

t1 = -153.1526

t2 = -2.8030

t3 = 4.8641

function [t1, t2, t3] = fcn(x, y, z)
    l1      = 0.1;
    l2      = 0.1;
    l3      = 0.045;
    epsilon = 0.001;
    
    % call local function 'compute_inv()'
    t       = compute_inv(x, y ,z, l1, l2,l3, epsilon);
    t1      = t(1);
    t2      = t(2);
    t3      = t(3);
    
    %% compute_inv
    function param_vec = compute_inv(x, y, z, l1, l2 ,l3, epsilon);
        t1              = pi/2;
        t2              = pi/2;
        t3              = pi/2;
        readings_t1     = t1;
        readings_t2     = t2;
        readings_t3     = t3;
        param_vec       = [t1, t2, t3]';     % <-- fix here or make it a column vector
        F_n             = roots_fn_inv(x, y, z, t1, t2, t3, l1, l2, l3);
        n               = 1;
        while norm(F_n) > epsilon
            F_n_dash    = drev_roots_fn_inv(t1, t2, t3, l1, l2, l3);
            param_vec   = param_vec - F_n_dash\F_n;
            t1          = param_vec(1);
            t2          = param_vec(2);
            t3          = param_vec(3);
            F_n         = roots_fn_inv(x, y, z, t1, t2, t3, l1, l2, l3);
            n           = n + 1;
        end
    end
    
    %% roots_fn_inv
    function f = roots_fn_inv(x, y, z, t1, t2, t3, l1, l2, l3)
        f = [l1*cos(t1)*(cos(t2+t3)+cos(t2))-x;
            l2*sin(t1)*(cos(t2+t3)+cos(t2))-y;
            l1*sin(t2+t3)+l1*sin(t2)+l3-z];
    end
    
    %% drev_roots_fn_inv
    function f_dash = drev_roots_fn_inv(t1, t2, t3, l1, l2, l3)
        f_dash = [-(sin(t1)*(cos(t2+t3)+cos(t2)))/10 -(cos(t1)*(sin(t2 + t3)+sin(t2)))/10 -(sin(t2 + t3)*cos(t1))/10;
                   (cos(t1)*(cos(t2+t3)+cos(t2)))/10 -(sin(t1)*(sin(t2 + t3)+sin(t2)))/10 -(sin(t2 + t3)*sin(t1))/10;
                   0 cos(t2+t3)/10+cos(t2)/10 cos(t2+t3)/10];
    end
end

[alaa]

ty