Gnuplot pm3d调色板颜色未映射到指定的值？

我正试图绘制太阳光谱图。我很难将我指定的颜色映射到正确的值。这是我的剧本

set view map
set pm3d 
set palette defined (380 "purple", 475 "blue", 510 "green", 570 "yellow", 590 "orange", 650 "red", 675 "dark-red", 700 "black")
splot [400:800][0:1] x

---

正如您在x=510处看到的，该图不是绿色的。同样，570处也不是我指定的黄色。如何解决此问题，使绘图上的颜色与我指定的颜色匹配？

我需要指定

cbrange

以匹配绘图范围，例如

set view map
set pm3d 
set palette defined (400 "purple", 475 "blue", 510 "green", 570 "yellow", 590 "orange", 650 "red", 675 "dark-red", 700 "black")
splot [400:700][0:1] x
set cbrange [400:700]

---

以便正确缩放颜色。

我需要指定

cbrange

以匹配绘图范围，例如

set view map
set pm3d 
set palette defined (400 "purple", 475 "blue", 510 "green", 570 "yellow", 590 "orange", 650 "red", 675 "dark-red", 700 "black")
splot [400:700][0:1] x
set cbrange [400:700]

以便正确缩放颜色