code: public static void mult(double alpha , DMatrix1Row a , DMatrix1Row b , DMatrix1Row c )
      {
          // TODO add a matrix vectory multiply here
          if( b.numCols >= EjmlParameters.MULT_COLUMN_SWITCH ) {
              MatrixMatrixMult_DDRM.mult_reorder(alpha, a, b, c);
          } else {
              MatrixMatrixMult_DDRM.mult_small(alpha,a,b,c);
          }
      }
docs: <p>Performs the following operation:<br>
  <br>
  c = &alpha; * a * b <br>
  <br>
  c<sub>ij</sub> = &alpha; &sum;<sub>k=1:n</sub> { * a<sub>ik</sub> * b<sub>kj</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.