Matrix dimensions must agree.

??? Error using ==> plus
Matrix dimensions must agree.

Error in ==> assem at 28
      K(t(i,:),t(i,:)) = K(t(i,:),t(i,:))+Ke;

Dear all, What the hell is this? what should I do? please help me out.

thanks

function [Ke]=bar3e(ex,ey,ez,ep)

    %--------------------------------------------------------------------
      E=ep(1);  A=ep(2); 

      b=[ ex(2)-ex(1); ey(2)-ey(1); ez(2)-ez(1) ];
      L=sqrt(b'*b);

      Kle=E*A/L*[1 -1;
                -1  1];

      n=b'/L;   G=[   n   zeros(size(n));
                    zeros(size(n))   n   ]; 

      Ke=G'*Kle*G;
    %--------------------------end--------------------------------

    function [K,f]=assem(edof,K,Ke,f,fe)
    %-------------------------------------------------------------
        [nie,n]=size(edof);
        t=edof(:,2:n);
        for i = 1:nie
          K(t(i,:),t(i,:)) = K(t(i,:),t(i,:))+Ke;
          if nargin==5
             f(t(i,:))=f(t(i,:))+fe;
          end
        end
    %--------------------------end--------------------------------

[dpb]

dbstop on error

Then

size(K(t(i,:),t(i,:)))
size(Ke)

They've got to be commensurate...and aren't presently.

[Hamid]

size(K(t(i,:),t(i,:))) = 4 * 4

size(Ke) = 6 * 6

But I don't know how to fix it.

Can you help me??

what I should do?

Thanks you so much.

[Matt J]

Only you can know how the code is supposed to behave. What dimensions do you expect these matrices to have?

[Georgi Gergov]

See the matrix dimension , that is the problem.

[Hamid]

size(K(t(i,:),t(i,:))) = 4 * 4

on the other hand I want

(K(t(i,:),t(i,:))) size

change to 6*6 but it seems K is 9*9 matrix!!!!

What should I do?

Thanks guys.

Answer 1

[Rick Rosson]

   doc dbstop
   doc dbcont
   doc dbquit
   doc dbstep

[Hamid]

size(K(t(i,:),t(i,:))) = 4 * 4

on the other hand I want

(K(t(i,:),t(i,:))) size

change to 6*6 but it seems K is 9*9 matrix!!!!

What should I do?

Thanks guys.