如何用 ggplot2 图例中的空格替换下划线？

Question

我输入的 csv 文件（“genus_counts.csv”）的前几行如下所示

Sample,Woeseia,Candidatus_Nitrosopumilus,Nitrospira,Nitrospina,Pseudahrensia,AqS1,Salinicola,Pir4_lineage,Subgroup_10,BD1-7_clade,Sva0996_marine_group,Anoxybacillus,Others,Unclassified
BW1,1.73959,0.474433,0,1.15973,0,0,3.32103,0,0,0,0,8.69794,27.464423,57.1429
BW2,0.424628,0.679406,0,0,0,0,9.95754,0,0.191083,0,1.18896,0,35.7749522,51.7834

我打算以此为基础制作堆积条形图。 我尝试了下面的 R 代码，但图例上的名称仍然带有下划线。 我引入了行pcm %>% rename_all(~gsub("_", " ", .))以便用空格替换所有下划线，但图例没有任何变化（下划线保留在 plot 上。）。 这里的任何帮助将不胜感激。

library(ggplot2)
library(reshape2)
pc = read.csv("genus_counts.csv", header = TRUE)
pcm = melt(pc, id = c("Sample"))
pcm$Sample <- factor(pcm$Sample,levels=unique(pcm$Sample))
pcm %>% rename_all(~gsub("_", " ", .))
mx = ggplot(pcm, aes(x = Sample, fill = variable, y = value)) + 
    geom_bar(stat = "identity", colour = "black") + 
    theme(axis.text.x = element_text(angle = 90, size = 14, colour = "black", vjust = 0.5, hjust = 1, face= "bold"), 
    axis.title.y = element_text(size = 16, face = "bold"), legend.title = element_text(size = 16, face = "bold"), 
    legend.text = element_text(size = 12, face = "bold", colour = "black"), 
    axis.text.y = element_text(colour = "black", size = 12, face = "bold")) + 
    scale_y_continuous(expand = c(0,0)) + 
    labs(x = "", y = "Relative Abundance (%)", fill = "Taxon") + 
    scale_fill_viridis_d(option="plasma")
mx

Answer 1

rename_all用于更改function的列名。 melt dataframe后，变量不再是列名，而是variable列的值。

因此，您可以在melt步骤之前使用rename_all ，也可以在熔化 dataframe 之后替换mutate语句中的值。

library(dplyr)
library(ggplot2)

pcm %>%
  mutate(variable = gsub("_", " ", variable)) %>%
  ggplot(aes(x = Sample, fill = variable, y = value)) + 
  geom_bar(stat = "identity", colour = "black") + 
  theme(axis.text.x = element_text(angle = 90, size = 14, 
          colour = "black", vjust = 0.5, hjust = 1, face= "bold"), 
        axis.title.y = element_text(size = 16, face = "bold"), 
          legend.title = element_text(size = 16, face = "bold"), 
        legend.text = element_text(size = 12, face = "bold", colour = "black"), 
        axis.text.y = element_text(colour = "black", size = 12, face = "bold")) +
  scale_y_continuous(expand = c(0,0)) + 
  labs(x = "", y = "Relative Abundance (%)", fill = "Taxon") + 
  scale_fill_viridis_d(option="plasma")

Answer 2

实现所需结果的第二个选项是将 function 传递给 scale 的labels参数，用空格替换下划线，即labels = ~ gsub("_", " ", .x) ：

library(ggplot2)
library(reshape2)

pcm <- melt(pc, id = c("Sample"))
pcm$Sample <- factor(pcm$Sample, levels = unique(pcm$Sample))

ggplot(pcm, aes(x = Sample, fill = variable, y = value)) +
  geom_bar(stat = "identity", colour = "black") +
  theme(
    axis.text.x = element_text(angle = 90, size = 14, colour = "black", vjust = 0.5, hjust = 1, face = "bold"),
    axis.title.y = element_text(size = 16, face = "bold"), legend.title = element_text(size = 16, face = "bold"),
    legend.text = element_text(size = 12, face = "bold", colour = "black"),
    axis.text.y = element_text(colour = "black", size = 12, face = "bold")
  ) +
  scale_y_continuous(expand = c(0, 0)) +
  labs(x = "", y = "Relative Abundance (%)", fill = "Taxon") +
  scale_fill_viridis_d(option = "plasma", labels = ~ gsub("_", " ", .x))

数据

pc <- structure(list(
  Sample = c("BW1", "BW2"), Woeseia = c(
    1.73959,
    0.424628
  ), Candidatus_Nitrosopumilus = c(0.474433, 0.679406),
  Nitrospira = c(0L, 0L), Nitrospina = c(1.15973, 0), Pseudahrensia = c(
    0L,
    0L
  ), AqS1 = c(0L, 0L), Salinicola = c(3.32103, 9.95754),
  Pir4_lineage = c(0L, 0L), Subgroup_10 = c(0, 0.191083), BD1.7_clade = c(
    0L,
    0L
  ), Sva0996_marine_group = c(0, 1.18896), Anoxybacillus = c(
    8.69794,
    0
  ), Others = c(27.464423, 35.7749522), Unclassified = c(
    57.1429,
    51.7834
  )
), class = "data.frame", row.names = c(NA, -2L))