Rggplot2-调整连续色条渐变上的中断之间的距离

我在中创建了一个热图，并ggplot2使用geom_tile映射了值scale_fill_gradientn。色标分为两个渐变。一个梯度将值从0映射到0.05，另一个梯度将值从0.05映射到1。我希望红黄色渐变（0-0.05）具有与黑褐色渐变（0.05-1）相同的高度。

问题：如何修改颜色条，以使值0.05位于条的中间/中央，从而使两个不同的颜色渐变的高度相同？

换句话说，假设0.05刻度线是一个滑块，您可以将其移动到扩展/压缩各个渐变的条的中间。

以下两篇文章讨论了类似的问题，但没有最终解决方案，或者至少没有我可以轻易理解并回答我的问题的解决方案：

类似问题1

类似的问题2

非常感谢大家阅读我的问题并思考可能的解决方案。到目前为止，除了在Photoshop中编辑颜色栏外，我什么都找不到。彼得

可重现的示例：

TEST <- read.csv ("https://filetea.me/n3wHRhuy0GlS4xvjQDxs95BVA",header=T,row.names=NULL)

library(ggplot2) 
ggplot(TEST, aes(x=Measure, y=SMTSD))+
    geom_tile(aes(fill=Pval),colour="grey50", size=0.1) +
    scale_x_discrete(expand = c(0,0))+
    coord_equal(ratio=1)+

scale_fill_gradientn(colours=c("red","yellow","black","#996633"),
    values=c(0,0.0499,0.05,1),
    na.value="white", guide="colourbar",
    name="P-value",limits=c(0,1),breaks=c(0,0.05,1))+

 guides(fill = guide_colourbar(barheight = 20, direction = "vertical",
        title.position="top", title.hjust = 0.5,title.vjust = 0.5, nbin = 50))

Adam Quek.. 5

更改scale_fill_gradient值和中断将为您提供所需的内容：

ggplot(TEST, aes(x=Measure, y=SMTSD))+
  geom_tile(aes(fill=Pval^0.2313782),colour="grey50", size=0.1) +
  scale_x_discrete(expand = c(0,0))+
  coord_equal(ratio=1)+
  scale_fill_gradientn(colours=c("red","yellow","black","#996633"),
                       values=c(0,0.0499,0.05,1)^ 0.2313782,
                       na.value="white", guide="colourbar",
                       name="P-value",limits=c(0,1),breaks=c(0,0.05,1)^ 0.2313782, 
                       labels=c(0,0.05,1))+
  guides(fill = guide_colourbar(barheight = 20, direction = "vertical",
                               title.position="top", title.hjust = 0.5,title.vjust = 0.5, nbin = 50))

用新图像编辑的ps

更改scale_fill_gradient值和中断将为您提供所需的内容：

ggplot(TEST, aes(x=Measure, y=SMTSD))+
  geom_tile(aes(fill=Pval^0.2313782),colour="grey50", size=0.1) +
  scale_x_discrete(expand = c(0,0))+
  coord_equal(ratio=1)+
  scale_fill_gradientn(colours=c("red","yellow","black","#996633"),
                       values=c(0,0.0499,0.05,1)^ 0.2313782,
                       na.value="white", guide="colourbar",
                       name="P-value",limits=c(0,1),breaks=c(0,0.05,1)^ 0.2313782, 
                       labels=c(0,0.05,1))+
  guides(fill = guide_colourbar(barheight = 20, direction = "vertical",
                               title.position="top", title.hjust = 0.5,title.vjust = 0.5, nbin = 50))

用新图像编辑的ps