code: public static void elementMult( DMatrix2x2 a , DMatrix2x2 b , DMatrix2x2 c ) {
          c.a11 = a.a11*b.a11; c.a12 = a.a12*b.a12;
          c.a21 = a.a21*b.a21; c.a22 = a.a22*b.a22;
      }
docs: <p>Performs an element by element multiplication operation:<br>
  <br>
  c<sub>ij</sub> = a<sub>ij</sub> * b<sub>ij</sub> <br>
  </p>
  @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.