MATLAB: Am I receiving a “Size argument must be constant” error when compiling the Embedded MATLAB code in Simulink 7.5 (R2010a)

Question

When I compile the following Embedded MATLAB code:

function y  = StructInitialization
      A.B=5;
      C= repmat([1 2 3], 1, A.B);
      y=0;
end

I receive the following error:

 Size argument must be constant.
 Function 'Embedded MATLAB Function' (#29.54.77), line 3, column 8:
 "repmat([1 2 3], 1, A.B)"
 Launch diagnostic report.

Answer 1

This error occurs because constant-folding does not work on structures which are initialized on a field-by-field basis.

To avoid this error, rewrite the expression:

A.B=5;

as

A=struct('B',5);