code: public static void multTransAB( double alpha , DMatrix2x2 a , DMatrix2x2 b , DMatrix2x2 c) {
          c.a11 = alpha*(a.a11*b.a11 + a.a21*b.a12);
          c.a12 = alpha*(a.a11*b.a21 + a.a21*b.a22);
          c.a21 = alpha*(a.a12*b.a11 + a.a22*b.a12);
          c.a22 = alpha*(a.a12*b.a21 + a.a22*b.a22);
      }
docs: <p>
  Performs the following operation:<br>
  <br>
  c = &alpha;*a<sup>T</sup> * b<sup>T</sup><br>
  c<sub>ij</sub> = &alpha;*&sum;<sub>k=1:n</sub> { a<sub>ki</sub> * b<sub>jk</sub>}
  </p>
  
  @param alpha Scaling factor.
  @param a The left matrix in the multiplication operation. Not modified.
  @param b The right matrix in the multiplication operation. Not modified.
  @param c Where the results of the operation are stored. Modified.