You can create an mxArray as you would anywhere else, e.g.
mxArray* myArray = mxCreateDoubleMatrix( 3, 4, mxREAL );
double* dataPtr = mxGetPr( myArray );
// Some code here to fill up myArray however you want using dataPtr
mxSetField( plhs[0], 0, field_names{1}, myArray ); // Assign matrix to first field name of 1st structure in array
mxSetField( plhs[1], 1, field_names{1}, myOtherArray ); // Assign matrix to first field name of 2nd structure in array
etc
with myOtherArray created by whatever method you choose also.
Best Answer