geom_tile单色为0，然后是色阶 [英] geom_tile single color as 0, then color scale

问题描述

我想生成一张热图，其中的颜色托盘为绿色至红色，但值为0时为白色。我开始使用
但是我希望等于零的值为白色。因此，这部分内容会在这里出现：

  ggplot（df，aes（x = Var1，y = Var2，fill = z）） + 
 geom_tile（）+ 
 scale_fill_gradient（low =green，high =red，limits = c（1，10））
  

绿色变红：

  ggplot（df，aes（x = Var1，y = Var2，fill = z））+ 
 geom_tile（）+ 
 scale_fill_gradient（low =white，high =red）
  

我根本无法使用啤酒秤（尽管我认为我很缺乏

  ggplot（df，aes（x = Var1，y = Var2，fill = z） ）+ 
 geom_tile（）+ 
 scale_fill_brewer（Greens）
  

错误：连续提供给离散量表的值

我应该用0代替NA吗？任何帮助，将不胜感激。

解决方案

您可以使用 scale_fill_gradientn（）：

  ggplot（df，aes（x = Var1，y = Var2，fill = z））+ 
 geom_tile（）+ 
 scale_fill_gradientn（colors = c（white，green，red），values = c（0,0.1,1））
  

I want to produce a heat map where with a color pallet of green to red, but values of 0 are in white. I got started with geom_tile heatmap with different high fill colours based on factor and others on SO but can't quite get what I need. For example, with the following database:

df <- data.frame(expand.grid(1:10,1:10))
df$z <- sample(0:10, nrow(df), replace=T)

I can create this plot:

ggplot(df,aes(x = Var1,y = Var2,fill = z)) + 
  geom_tile() + 
  scale_fill_gradient(low = "green", high = "red")

But I want the values equal to zero to be white. So this gets part way there:

ggplot(df,aes(x = Var1,y = Var2,fill = z)) + 
  geom_tile() + 
  scale_fill_gradient(low="green", high="red", limits=c(1, 10))

And this gets 0 as white but I lose the green to red:

ggplot(df,aes(x = Var1,y = Var2,fill = z)) + 
  geom_tile() + 
  scale_fill_gradient(low = "white", high = "red")

And I can't use brewer scales at all (though I think I'm missing something simple based on the error).

ggplot(df,aes(x = Var1,y = Var2,fill = z)) + 
  geom_tile() + 
  scale_fill_brewer("Greens")

Error: Continuous value supplied to discrete scale

Should I just replace 0 with NA? Any help would be appreciated.

解决方案

You can use scale_fill_gradientn():

ggplot(df,aes(x = Var1,y = Var2, fill = z)) + 
  geom_tile() + 
  scale_fill_gradientn(colours = c("white", "green", "red"), values = c(0,0.1,1))

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