如何在 gnuplot 轮廓图上添加箭头？

Question

我有一个双重流的轮廓图，但我正尝试在轮廓图上添加箭头。

 \begin{axis}[ xshift=8cm,
    ticks = none,
    view={0}{90},
    xmin = -1, ymin = -3,
    xmax = 5, ymax= 3,
    axis background/.style={fill=white} ]

       \addplot3 [ samples=101,smooth,  contour gnuplot={levels={-2.5,-1.75,-1,-0.75,-0.5,-0.4,0,0.4,0.5,0.75,1,1.75,2.5}, draw color = black, labels=false, }] {0-y/((x-2)^2 + y^2)};
        \addplot3 [ samples=101,smooth, contour gnuplot={levels={-2.5,-1.75,-1,-0.75,-0.5,-0.4,0,0.4,0.5,0.75,1,1.75,2.5}, draw color = red, labels=false}] {(x-2)/((x-2)^2 + y^2)};


\end{axis}

我尝试过使用装饰，但不起作用。下面是带有红色箭头的示例。