Having trouble with for loop function. Displays only last value.

My loop function "for el = 1:ne" only displays the last value of ke when I would like it to display a number equal to the number of elements I input into my LM.mat file. If I put 3 elements I should have 3 ke matricies.

Basically, I want to be able to view all ke values and the assembled value of Kg as output. So if I have 3 elements I want to view the output as seen below.

ke = [ x x x x
       x x x x;
       x x x x;
       x x x x]
ke = [ x x x x
       x x x x;
       x x x x;
       x x x x]
ke = [ x x x x
       x x x x;
       x x x x;
       x x x x]
Kg = [ x x x x x x
       x x x x x x;
       x x x x x x;
       x x x x x x;
       x x x x x x;
       x x x x x x]

The function is:

function [ke Kg] = AnalyzeTruss(Coord,LM,N,ndof,NNE)
% N = No. of elements (say 3)
% ndof = No. of degrees of freedom per node (say 2)
% NNE = No. of nodes per element (say 2)
% Coord.mat = (x-cord, y-coord)
% LM.mat = (node 1, node 2, A, E)
[ne,~] = size(LM);
for el = 1:ne
  E = LM(el,3);
  A = LM(el,4);
  iNode = LM(el,1);
  jNode = LM(el,2);
end
iNodeX = Coord(iNode,1);
iNodeY = Coord(iNode,2);
jNodeX = Coord(jNode,1);
jNodeY = Coord(jNode,2);
L = sqrt((jNodeX - iNodeX)^ 2 + (jNodeY - iNodeY)^ 2);
c = (jNodeX - iNodeX)/L;
s = (jNodeY - iNodeY)/L;
c2 = c^2;
s2 = s^2;
ke = (E*A/L)*[c2 c*s -c2 -c*s;
              c*s s2 -c*s -s2;
              -c2 -c*s c2 c*s;
              -c*s -s2 c*s s2];
Kg=zeros(N*ndof);
for i=1:NNE
    index_i=ndof*(i-1);
    index_I=ndof*(LM(el,i)-1);
    for j=1:NNE
        index_j=ndof*(j-1);
        index_J=ndof*(LM(el,j)-1);
        for d1=1:ndof
            for d2=1:ndof
                Kg(index_I+d1,index_J+d2)=ke(index_i+d1,index_j+d2);
            end
        end
    end
end

Thanks, if anyone can help me!

Cody Davis

Answer 1

[Star Strider]

I can’t run your code because I don’t have all the data, but it would seem that removing the semicolons from the ends of the statements for ke and Kg might do what you want. (Semicolons suppress the output of a specific line in MATLAB.)