docs: public static void multAddOuter( double alpha , DMatrix3x3 A , double beta , DMatrix3 u , DMatrix3 v , DMatrix3x3 C ) {
          C.a11 = alpha*A.a11 + beta*u.a1*v.a1;
          C.a12 = alpha*A.a12 + beta*u.a1*v.a2;
          C.a13 = alpha*A.a13 + beta*u.a1*v.a3;
          C.a21 = alpha*A.a21 + beta*u.a2*v.a1;
          C.a22 = alpha*A.a22 + beta*u.a2*v.a2;
          C.a23 = alpha*A.a23 + beta*u.a2*v.a3;
          C.a31 = alpha*A.a31 + beta*u.a3*v.a1;
          C.a32 = alpha*A.a32 + beta*u.a3*v.a2;
          C.a33 = alpha*A.a33 + beta*u.a3*v.a3;
      }