R用颜色表示范围内的值的scale_fill_manual

Question

我只是希望清理我的代码，学习一两件事。我觉得我让这件事变得更难了。我有0-9的数据范围，我想为这个范围内的值指定一个颜色。例如：

0-3 green
4-6 yellow
7-9 red

这是我唯一能让它运转的方法。我觉得应该有一种方法来指定间隙的范围。即0-3 =绿色等

ggplot() +
  geom_raster(data = data, aes(x = samples, y = organism, fill = as.factor(value))) +
  scale_fill_manual(values=c("green", "green", "green","green", "yellow","yellow","yellow", "red","red", "red"), breaks=c(0,1,2,3,4,5,6,7,8,9))

下面的代码工作正常，但是每当我试图在中断中创建一个范围时，我都会得到错误：

breaks=c(0-3,4-6,7-9)
Error: Insufficient values in manual scale. 10 needed but only 3 provided.

我希望这是相当清楚的解释。如果需要，我可以提供一个样本数据集(如下)。谢谢您抽时间见我!

samples,organism,value
a,z,0
b,z,1
c,z,2
d,z,3
e,z,4
f,z,5
g,z,6
h,z,7
i,z,8
j,z,9

Answer 1

我没有你的数据，但我做了一些看上去像你的：

set.seed(123)
data <- expand.grid(samples = 1:5, organism = LETTERS[1:4])
data$value <- sample(0:9, 20, replace = TRUE)

使用这些数据，运行您的代码时会出现一个不同的错误：

ggplot() +
  geom_raster(data = data, aes(x = samples, y = organism, fill = value)) +
  scale_fill_manual(values=c("green", "green", "green", "green", "yellow", "yellow", "yellow", "red", "red", "red"), 
                    breaks=c(0,1,2,3,4,5,6,7,8,9))
Error: Continuous value supplied to discrete scale

如果我将value转换为一个因子，则不会出现错误。我需要你的数据来帮助诊断错误。

ggplot() +
  geom_raster(data = data, aes(x = samples, y = organism, fill = factor(value))) +
  scale_fill_manual(values=c("green", "green", "green", "green", "yellow", "yellow", "yellow", "red", "red", "red"), 
                    breaks=c(0,1,2,3,4,5,6,7,8,9))

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使用我的数据，这里有一种更简单的方法(特别是如果value是连续的)：

ggplot() +
  geom_raster(data = data, aes(x = samples, y = organism, 
                               fill = cut(value, breaks = c(0, 3, 6, 9)))) +
  scale_fill_manual(name = "value", 
                    values = c("green", "yellow", "red"),
                    labels = c("0-3", "4-6", "7-9"))

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