scale_gradientn中的陡峭梯度 [英] Steeper gradients in scale_gradientn

问题描述

使用 R 中的 ggplot2 ，我可以获得如下所示的离散色标：
< a href = https://i.stack.imgur.com/7g4mf.png rel = nofollow noreferrer>

这可以生成，如

显然这还不够好，因为可以在4个级别之间看到明显的色彩偏移

在ggplot2中完全有可能吗？

解决方案

使用离散量表：

  library（ggplot2）
 faithfuld $ classs< ;-cut（忠实的$密度，c（-Inf，0.01，0.02，0.03，Inf））
 ggplot（忠实的，aes（等待，爆发））+ 
 geom_raster（aes（fill = classes） ）+ 
 scale_fill_manual（name = density，
 values = c（ red， green， blue， yellow），
标签= c（0.01，0.02 ，0.03，））+ 
指南（fill = guide_legend（label.vjust = -0.2））
  

Using ggplot2 in R, I can obtain a discrete color scale like the following:

This can be generated as seen here.

However, it does not look great. I'd like ro remove the spacing between the levels, and I thought that maybe I could switch to a continuous color scale, using scale_gradientn() and having a very steep gradient between different colors. This way I could use a continuous color scale, which has labels in the right places and looks great, instead of a discrete one.

However, this is the best I could come up with:

library(ggplot2)
ggplot(faithfuld, aes(waiting, eruptions)) +
  geom_raster(aes(fill = density)) +
  scale_fill_gradientn(
    colours = c("red", "green", "blue", "yellow"), 
    values=c(0, 0.25, 0.25001, 0.5, 0.5001, 0.75, 0.75001,1)
  )

Which clearly is not good enough, as significant color shifting can be seen between the 4 levels.

Is this possible at all in ggplot2?

解决方案

Just use a discrete scale:

library(ggplot2)
faithfuld$classes <- cut(faithfuld$density, c(-Inf, 0.01, 0.02, 0.03, Inf))
ggplot(faithfuld, aes(waiting, eruptions)) +
  geom_raster(aes(fill = classes)) +
  scale_fill_manual(name = "density",
                    values = c("red", "green", "blue", "yellow"),
                    labels = c(0.01, 0.02, 0.03, "")) +
  guides(fill = guide_legend(label.vjust = -0.2))

这篇关于scale_gradientn中的陡峭梯度的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！