如何在R中使用ggplot2創建具有連續比例的熱圖

Question

我有一個包含幾千行的數據框，形式為

group = c("gr1","gr1","gr1","gr1","gr1","gr1","gr1","gr1","gr1","gr1","gr2","gr2","gr2","gr2","gr2","gr2","gr2","gr2","gr2","gr2","gr3","gr3","gr3","gr3","gr3","gr3","gr3","gr3","gr3","gr3")
pos = c(1,2,3,4,5,6,7,8,9,10,1,2,3,4,5,6,7,8,9,10,1,2,3,4,5,6,7,8,9,10)
color = c(2,2,2,2,3,3,2,2,3,2,1,2,2,2,1,1,1,1,1,1,2,2,2,2,2,2,1,1,2,2)
df = data.frame(group, pos, color)

並想制作一種熱圖，其中一個軸具有連續的比例（位置）。 顏色列是分類的。 但是由於大量的數據點，我想使用裝箱，即將其用作連續變量。

這大致相當於情節的樣子：

我想不出一種使用ggplot2 / R創建這樣的圖的方法。 我嘗試了幾種幾何，例如geom_point（）

ggplot(data=df, aes(x=strain, y=pos, color=color)) + 
  geom_point() +
  scale_colour_gradientn(colors=c("yellow", "black", "orange"))

感謝您的幫助。

Answer 1

這對您有幫助嗎？

library(ggplot2)
group = c("gr1","gr1","gr1","gr1","gr1","gr1","gr1","gr1","gr1","gr1","gr2","gr2","gr2","gr2","gr2","gr2","gr2","gr2","gr2","gr2","gr3","gr3","gr3","gr3","gr3","gr3","gr3","gr3","gr3","gr3")
pos = c(1,2,3,4,5,6,7,8,9,10,1,2,3,4,5,6,7,8,9,10,1,2,3,4,5,6,7,8,9,10)
color = c(2,2,2,2,3,3,2,2,3,2,1,2,2,2,1,1,1,1,1,1,2,2,2,2,2,2,1,1,2,2)
df = data.frame(group, pos, color)
ggplot(data = df, aes(x = group, y = pos)) + geom_tile(aes(fill = color)) 

看起來像這樣

如果您願意，可提供帶有3種顏色漸變的改進版本

library(scales)
ggplot(data = df, aes(x = group, y = pos)) + geom_tile(aes(fill = color))+ scale_fill_gradientn(colours=c("orange","black","yellow"),values=rescale(c(1, 2, 3)),guide="colorbar")