如何解决ggplot中geom_bar的geom_text_repel标签重叠问题？

已尝试调整box.padding、max.overlaps、min.segment.length参数，仍无法拉开重叠的标签。相关R代码及问题截图如下：

data = read.csv("995_matched_cancer_types.csv", header=T)
names(data) <- c("cancer_types","primary_disease","cell_lines")
data <- subset(data, data$primary_disease!="Unknown")
data["counts"] <- data$cell_lines/sum(data$cell_lines)
data["info"] <- paste0(data$cancer_types,"(",data$cell_lines,")")


ggplot(data, aes(x=1, y=counts, label=info, fill=cancer_types)) +
  geom_bar(stat="identity", position = position_dodge2(), color="black") +
  geom_text_repel(position=position_dodge2(.9), 
                  box.padding = .5,
                  max.overlaps = 30,
                  min.segment.length = 0,
                  ylim = c(.03,Inf)) +
  labs(x = NULL, y = NULL, fill = NULL)+
  theme_classic() + theme(axis.line.x = element_blank(),
                          axis.text.x = element_blank(),
                          axis.ticks.x = element_blank(),
                          strip.text = element_text(size = 12),
                          legend.position = "none"
                          )+
  facet_wrap(~primary_disease)

以下几个调整方向可尝试解决标签重叠问题：

1. 缩小标签字体，减少占用空间 #

在geom_text_repel中加入size参数缩小字体，降低单个标签的宽度：

geom_text_repel(position=position_dodge2(.9), 
                box.padding = .5,
                max.overlaps = 30,
                min.segment.length = 0,
                ylim = c(.03,Inf),
                size=3) # 新增缩小字体参数

2. 扩大柱子间距，让标签同步分散 #

调大position_dodge2的数值，增加柱子之间的空隙，标签也会随之分散：

geom_bar(stat="identity", position = position_dodge2(1.2), color="black") +
geom_text_repel(position=position_dodge2(1.2), 
                box.padding = .5,
                max.overlaps = 30,
                min.segment.length = 0,
                ylim = c(.03,Inf))

3. 调整标签方向，避免横向挤压 #

给geom_text_repel添加angle参数让标签倾斜，或设置direction="y"让标签垂直排列：

# 标签倾斜45度
geom_text_repel(position=position_dodge2(.9), 
                box.padding = .5,
                max.overlaps = 30,
                min.segment.length = 0,
                ylim = c(.03,Inf),
                angle=45)

# 标签垂直排列
geom_text_repel(position=position_dodge2(.9), 
                box.padding = .5,
                max.overlaps = 30,
                min.segment.length = 0,
                ylim = c(.03,Inf),
                direction="y")

4. 扩大垂直显示范围，给标签更多空间 #

把ylim的下限调低，让标签可以向下延伸，避免在上方区域拥挤：

geom_text_repel(position=position_dodge2(.9), 
                box.padding = .5,
                max.overlaps = 30,
                min.segment.length = 0,
                ylim = c(0,Inf)) # 扩大垂直空间范围

5. 将标签移至柱子内部（适用于高度足够的柱子） #

如果柱子高度允许，把标签放在柱子内部，避免外部重叠：

geom_text_repel(position=position_dodge2(.9), 
                box.padding = .5,
                max.overlaps = 30,
                min.segment.length = 0,
                ylim = c(0, max(data$counts)*0.8), # 限制在柱子内部区域
                nudge_y = -0.01) # 向内偏移标签位置

内容的提问来源于stack exchange，提问作者Chih-Yuan Chou