交换对象'；在gnuplot中具有“front”键的s层

我避免自己冗长乏味的代码，只关注重要的事情。我用这两条线生产

set arrow from xarr_1, yarr_1 to xarr_2, yarr_2 nohead lc 'white' lw 2 front
set object circle at xarr_2, yarr_2 size screen 0.01 fc rgb "black" fillstyle solid 1.0 front 

下图中的黑色圆圈和白色区域（这是一堆箭头）（只有一个就足够了） 因为在两个对象上：箭头和圆圈，我使用键

front

将它们放在

plot

命令的前面，我现在希望黑色对象位于箭头“白色区域”的前面

我该怎么做

PS：无论您是否交换命令，此简化代码都会出现相同的问题

reset session 
reset
PI = 4.*atan(1.)
set xrange [-PI:PI]
set arrow from -0.1, 0.1 to 0.1, -0.1 lc 'black' lw 2 front 
set object circle at 0, 0 radius 0.1 fillstyle solid 1.0 fc rgb 'red' front 
plot  sin(x) w l 
pause -1 

---

如果查看gnuplot手册（

help layers

），对象的绘制顺序是：标签前面的箭头在对象前面（矩形、圆、椭圆、多边形）。据我所知，除非使用multiplot，否则不能在箭头前画圆。如果我没弄错你的问题，你想在箭头前画一个圆圈。所以，您可能必须使用multiplot

大概是这样的：

### plot circle in front of an arrow
reset session

set obj 999 rect from graph 0, graph 0 to graph 1, graph 1 fc rgb "black" behind
set print $Data   # create some random data
do for [i=1:1000] { print sprintf("%g %g", invnorm(rand(0)), invnorm(rand(0)))}
set print

set xrange[-3:3]
set yrange[-3:3]
set multiplot
    set arrow 1 from -1,1 to 1,-1 lc 'white' lw 3
    plot $Data u 1:2 w p pt 7 ps 1 lc rgb "red"

    set object 1 circle at 0,0 radius 0.5 fillstyle solid 1.0 fc rgb 'blue' front
    unset obj 999 # don't use the black background again
    plot -10 not  # plot some dummy out of range
unset multiplot
### end of code

给出如下内容：

### plot circle in front of an arrow
reset session

set obj 999 rect from graph 0, graph 0 to graph 1, graph 1 fc rgb "black" behind
set print $Data   # create some random data
do for [i=1:1000] { print sprintf("%g %g", invnorm(rand(0)), invnorm(rand(0)))}
set print

set xrange[-3:3]
set yrange[-3:3]
set multiplot
    set arrow 1 from -1,1 to 1,-1 lc 'white' lw 3
    plot $Data u 1:2 w p pt 7 ps 1 lc rgb "red"

    set object 1 circle at 0,0 radius 0.5 fillstyle solid 1.0 fc rgb 'blue' front
    unset obj 999 # don't use the black background again
    plot -10 not  # plot some dummy out of range
unset multiplot
### end of code