code: public static void multRow(Matrix A, int i, double c)
      {
          multRow(A, i, 0, A.cols(), c);
      }
docs: Updates the values of row <tt>i</tt> in the given matrix to be A[i,:] = A[i,:] * c
  
  @param A the matrix to perform he update on
  @param i the row to update
  @param c the constant to multiply each element by