fmincon - Index Exceeds Matrix Dimensions

Dear friends,

I am trying to plot a 3D truss structure together with "fmincon" function. I have got an error and couldn't find the problem.

However, the following errors are obtained :

Index exceeds matrix dimensions.

Error in Topo_3D/truss (line 164)
        elnodes = elem(iel, 1:3);

Error in Topo_3D/outfun (line 144)
            truss(x);

Error in callAllOptimOutputFcns (line 13)
    stop(i) = feval(OutputFcn{i},xOutputfcn,optimValues,state,varargin{:});

Error in barrier
Error in fmincon (line 798)
    [X,FVAL,EXITFLAG,OUTPUT,LAMBDA,GRAD,HESSIAN] =
    barrier(funfcn,X,A,B,Aeq,Beq,l,u,confcn,options.HessFcn, ...

Error in Topo_3D (line 30)
[x,fval,ef,output,lambda,hessian] = fmincon(objective,x0,A,b,Aeq,beq,lb,ub,nonlincon,options);

A copy of my fmincon function is attached.

I appreciate if somebody can help with this errors and how can it be solved.

Thank you very much!

RTFQ

[Ameer Hamza]

I cannot run your code because it require the file 'truss1.tcl'. But from the error message It appear that in the line

elnodes = elem(iel, 1:3);

you are trying to access elements in the matrix elem which does not exist. You can add breakpoint on this line to check the dimensions of elem matrix.

[Richard]

Mr Ameer thank you for your reply.

Yeah. The code supposedly to be elnodes = elem(iel, 1:2); since the element size is only 25x2. However, exactly the same errors still appeared.

Hope that Mr Ameer can give me some advices.

[Walter Roberson]

We do not have information about the format of the truss file.

What we can say is that if the z data exists in the truss file at all (not certain) then your code never reads it in.

[Richard]

Dear friends,

A copy of my truss1.tcl is attached in txt format.

Yeah, the code never reads my z data in.

Thanks.

[Ameer Hamza]

Richard, your code reads several other files too. Also, I suggest reading these files once, at the beginning of your code, and then pass the variables to your function. Reading files repeatedly will significantly slow down your code.

[Richard]

Thank you so much for your reply and help Mr Ameer!

Answer 1

[Walter Roberson]

        stread = textscan(st, '%s %f %d %d'); % textscan is reading formatted data from text file or string
        nd = [nd; stread{3}, stread{4}];

Change that to

        stread = textscan(st, '%s %f %f %f %f'); % textscan is reading formatted data from text file or string
        nd = [nd; stread{3}, stread{4}, strread{5}];

After that you should be able to

plot3(node(:,1), node(:,2),node(:,3),'k.')

[Richard]

Thank you so much for your quick response and help, Mr Walter.

It works perfectly to show as a 3D graph.