How to perform element-wise matrix multiplication in simulink?

Hi,

I have modelled the equations below in Simulink and I wanted to check them through simulation. But when modelled in Simulink they give an error.

 s_x_index = 0:0.0001:0.02;
 for  i = 1:length(s_x_index)
     x_a(i) = s_x_index(i);
    epsilon_x=1/4.*[(G.*pi.*a1.*b1.*c_11.*s_x_index)/(Q.*cof)];
    F=(2*Q*cof/pi).*[(k_A*epsilon_x)./(1+(k_A*epsilon_x).^2)+atan(k_S*epsilon_x)];

I have posted only few lines of the code and not the entire coding thinking that this is enough to explain, please let me know if you need further information.

Please find attached the block in the model which cause the error. The error is,

Error using test_file (line 429) Error evaluating parameter 'Value' in 'force/Constant7'

Caused by: Error using test_file (line 429) Inner matrix dimensions must agree.

The size of the parameters are given below,

 >> size(a1)

ans =

     1     1

 >> size(b1)

ans =

     1     1

 >> size(G)

ans =

     1     1

 >> size(c_11)

ans =

     1     1

 >> size(s_x_index)

ans =

     1   201

Please do help out.

Thanks.

Answer 1

[Oyeniyi]

Perhaps you want to ensure element-wise multiplication and division. The 2nd division in 'epsilon_x' is the matrix type. As you haven't given the size of the other parameters (Q, cof etc), one cannot know for sure the intended type of operation. Try

epsilon_x=1/4.*[(G.*pi.*a1.*b1.*c_11.*s_x_index)./(Q.*cof)]; F=(2*Q.*cof/pi).*[(k_A.*epsilon_x)./(1+(k_A.*epsilon_x).^2)+atan(k_S.*epsilon_x)];

[Priya]

Thanks for your reply. I tried your suggestion, but it didn't work. The thing is I don't have any problem with the coding, I'm just trying to model the same equation of F in Simulink. So I have to follow the coding to model this equation in Simulink.

>> size(Q)

ans =

     1     1

>> size(cof)

ans =

     1     1