如何增加ggplot2中分組條之間的空間？

Question

[在帖子末尾制作情節的數據和代碼]

使用ggplot，我繪制了帶有誤差條的條形圖，條形圖按兩個因子分組（一個在X軸上，一個在填充上）。 我想增加xaxis上各組之間的綠色距離 ，使圖更容易閱讀：

我在這里找到的stackoverflow上最接近的解決方案（有人在未回復的評論中提出了我的問題）， 這里 ， 這里 ，但是我沒有設法應用這些而沒有集中錯誤欄。 有人能指出我正確的參數進行調整嗎？

數據：

structure(list(Condition = c("Difficult", "Easy", "Difficult", 
"Easy", "Difficult", "Easy", "Difficult", "Easy", "Easy", "Difficult", 
"Easy", "Difficult"), Measure = c("Competence", "Competence", 
"Value", "Value", "Interest", "Interest", "JOL", "JOL", "Difficulty", 
"Difficulty", "Effort", "Effort"), mean = c(5.5, 4.72, 4.04, 
5.39, 3.51, 3.77, 4.34, 4.61, 3.51, 1.51, 3.44, 1.73), sd = c(1.26, 
1.62, 1.94, 1.34, 1.46, 1.46, 1.73, 1.68, 1.5, 0.86, 1.53, 1.1
), se = c(0.14, 0.18, 0.22, 0.15, 0.16, 0.16, 0.19, 0.19, 0.17, 
0.1, 0.17, 0.12), s.size = c(80, 80, 80, 80, 80, 80, 80, 80, 
80, 80, 80, 80)), .Names = c("Condition", "Measure", "mean", 
"sd", "se", "s.size"), row.names = c(NA, -12L), class = "data.frame")

這是：

   Condition    Measure mean   sd   se s.size
1  Difficult Competence 5.50 1.26 0.14     80
2       Easy Competence 4.72 1.62 0.18     80
3  Difficult      Value 4.04 1.94 0.22     80
4       Easy      Value 5.39 1.34 0.15     80
5  Difficult   Interest 3.51 1.46 0.16     80
6       Easy   Interest 3.77 1.46 0.16     80
7  Difficult        JOL 4.34 1.73 0.19     80
8       Easy        JOL 4.61 1.68 0.19     80
9       Easy Difficulty 3.51 1.50 0.17     80
10 Difficult Difficulty 1.51 0.86 0.10     80
11      Easy     Effort 3.44 1.53 0.17     80
12 Difficult     Effort 1.73 1.10 0.12     80

我用來制作情節的代碼（請原諒評論，我正在學習如何使用ggplot並發現它有助於記筆記）

library(ggplot2)
ggplot(DF, aes(x=Measure, y=mean,fill=Condition)) + 
  geom_bar(stat="identity",
           colour="black",    # Black outline for all
           position=position_dodge())+# Put bars side-by-side instead of stacked
  geom_errorbar(aes(ymin=mean-se, ymax=mean+se),
                position=position_dodge(.9), 
                width=.25)+
  #order the groups on the xaxis
  scale_x_discrete(limits = c("Interest", "Value","Effort","Difficulty","Competence","JOL"))+
  coord_cartesian(ylim=c(0,7)) +
  #change color of bars
  scale_fill_manual(values=c("#ffcc00ff","#ffffff"), name = "Condition") + 
  #change ticks on yaxis
  scale_y_continuous(breaks=seq(0,7,by =1)) + 
  geom_hline(yintercept=0) +
  geom_vline(xintercept=0)+
  theme_bw()+
  labs(x="", y = "Rating (0-7)")+
  theme(axis.line.y = element_line(color="black"),
        axis.title.y = element_text(margin = margin(r=8)),
        axis.title.x = element_text(margin = margin(r=25)),
        panel.background = element_rect(fill = NA),
        panel.grid.major = element_blank(),
        panel.border = element_blank())

Answer 1

怎么樣？ 1.按照建議使用geom_col而不是geom_bar 。 2.指定合適的position_dodge(0.5)和width=0.5和3.刪除不必要的代碼。

ggplot(d, aes(x=Measure, y=mean, fill=Condition)) + 
  geom_col(colour="black",width=0.5,    
           position=position_dodge(0.5)) +
  geom_errorbar(aes(ymin=mean-se, ymax=mean+se),
                position=position_dodge(0.5), width=.25)+
  scale_x_discrete(limits = c("Interest", "Value","Effort","Difficulty","Competence","JOL")) +
  scale_y_continuous(breaks=seq(0,7,by =1),limits = c(0,7), expand = c(0,0))+
  scale_fill_manual(values=c("#ffcc00ff","#ffffff"), name = "Condition") + 
  labs(x="", y = "Rating (0-7)")+
  theme_minimal() +
  theme(axis.line = element_line(color="black"),
        axis.ticks = element_line(color="black"),
        panel.border = element_blank())

Answer 2

感謝所有人和AntoniosK一起思考這個問題的鏈接，這個問題幫助我找到了一個適合我的解決方案（雖然感覺有些笨拙）：手動改變條形寬度，調整寬高比（寬度到高度的情節） ）在主題中，在錯誤欄中調整position_dodge以匹配欄的寬度：

geom_bar(width = 0.7)
theme(aspect.ratio = 3/5)
geom_errorbars(position=position_dodge(.7))

（我還將圖例移到了劇情的頂部，截圖中未顯示）