在两行以上使用上标时修复图例标题 - R ggplot2

我正在绘制我的研究区域的地图，但在编辑图例标题时遇到问题。 我需要它是“预计 40 年休耕期的水果生产率（水果 ha^-1）”，用四行写成。我可以使用 bquote() 将 -1 绘制为上标。但它创建了一个我无法提供的额外空间想办法把它去掉。只有当标题被分成多行时，才会出现多余的空格。 另外，表达式（atop（））创建上标，但一旦我尝试将其分成两行以上，它就不会显示第三行和第四行。

This is the Map with the extra space using bquote()

This is the Map with the four line title using expression(atop())

我确实尝试了在互联网上找到的不同解决方案，包括这个帖子 https://stackoverflow.com/questions/13223846/ggplot2-two-line-label-with-expression。但他们都用额外的空间绘制第四行，或者只绘制第一行或第二行。

下面是我正在使用的代码。欢迎任何帮助。 评论是不同的尝试。

Data = Spatial_dist_fallows.csv https://drive.google.com/file/d/10wbXaYUTFzVNgwMcKME8hCNbRcdf-Mut/view?usp=sharing

library(sf) #sf = simple feature
library(ggplot2)
library(dplyr)

PAECM_fallows <-read.csv("spatial_dist_fallows.csv")
PAECM_fallows_sp <- st_as_sf(PAECM_fallows,coords = c("X", "Y"),crs = "+proj=longlat +datum=WGS84 +no_defs")

custom_bins_fruit = c(0,60,120,180,240,1400)
PAECM_fallows_fruit <- PAECM_fallows_sp %>% 
  mutate(prod_cat_fallow = cut(prod_40, breaks= custom_bins_fruit),
         age_cat_fallow = cut(age, breaks = c(11,17,22,29,60)))


prod_map_PAECM_fruit<-ggplot()+
  geom_sf(data = PAECM_fallows_fruit,aes(size = prod_cat_fallow), shape = 18, show.legend = "point")+
  scale_size_manual(values= c(2,3,4,5,6),
                  # name = "Projected fruit\nproductivity in\nfallows in 40 yrs \n(fruits ha^-1)",
                  name = bquote("Projected fruit\nproductivity in\nfallows in 40 yrs \n( fruits"*ha^-1*")"),
                  # name = expression(paste("Projected fruit productivity\nin fallows in 40 yrs\n"),bquote(paste("("*fruits~ha^-1*")"))),#(Fruits/ha)
                  name = expression(atop("Projected fruit",
                                     "productivity in",
                                     "fallows in 40 yrs",
                                     "( fruits ha"^-1,")")),
                  breaks= c(NA,"(0,60]","(60,120]","(120,180]","(180,240]","(240,1.4e+03]"),
                  labels= c("NA","\u2264 60","60 - 120","120 - 180","180 - 240","> 240"),
                  guide = guide_legend(override.aes = list(linetype = "blank", shape = 18, fill = NA)))+
  # labs(size = expression(atop("Projected fruit\nproductivity in\nfallows in 40 yrs\n(fruits"*ha^-1*")", sep="")))+ #comment name line at the scale_size_manual
  # labs(size = bquote("Projected fruit productivity \nin fallows in 40 yrs \n( fruits"*ha^-1*")"))+ #comment name line at the scale_size_manual
  ggplot2::theme_minimal()+
  ggplot2::theme(legend.text.align=0.5,
                 legend.title.align = 0.5,
                 plot.background = element_blank(),
                 panel.grid = element_line(colour = "white"),
                 panel.background = element_rect(fill = "grey87", color = "white"))+#,
  coord_sf(xlim = c(-68.45,-68.2), ylim = c(-11.05,-10.8))
prod_map_PAECM_fruit

额外的问题。一旦我开始使用 bquote，我就无法使用 theme(legend.title.align = 0.5) 对齐标题文本，还有其他想法吗？

经过一些其他尝试后，我确实为图例标题提出了以下解决方案。

name = expression(atop("",
                       atop(textstyle("Projected fruit"),
                            atop(textstyle("productivity in"),
                                 atop(textstyle("fallows in 40 yrs"),
                                      atop(textstyle("(fruits ha"^-1*")"))))))),

我使用 textstyle() 来绘制具有相同大小的所有文本，否则每次调用 atop() 时都会将其绘制得更小。 atop() 在第一行和第二行之间创建一个空格，这就是为什么代码的第一行是 atop(""，所以第一行将是空白。

这是最终的代码和下面的地图。

library(sf) #sf = simple feature
library(ggplot2)
library(dplyr)

PAECM_fallows <-read.csv("spatial_dist_fallows.csv")
PAECM_fallows_sp <- st_as_sf(PAECM_fallows,coords = c("X", "Y"),crs = "+proj=longlat +datum=WGS84 +no_defs")

custom_bins_fruit = c(0,60,120,180,240,1400)
PAECM_fallows_fruit <- PAECM_fallows_sp %>% 
  mutate(prod_cat_fallow = cut(prod_40, breaks= custom_bins_fruit),
     age_cat_fallow = cut(age, breaks = c(11,17,22,29,60)))


prod_map_PAECM_fruit_legend_test<-ggplot()+
  geom_sf(data = PAECM_fallows_fruit,aes(size = prod_cat_fallow), shape = 18, show.legend = "point")+
  scale_size_manual(values= c(2,3,4,5,6),
              name = expression(atop("",
                                     atop(textstyle("Projected fruit"),
                                          atop(textstyle("productivity in"),
                                               atop(textstyle("fallows in 40 yrs"),
                                                    atop(textstyle("(fruits ha"^-1*")"))))))),
              breaks= c(NA,"(0,60]","(60,120]","(120,180]","(180,240]","(240,1.4e+03]"),
              labels= c("NA","\u2264 60","60 - 120","120 - 180","180 - 240","> 240"),
              guide = guide_legend(override.aes = list(linetype = "blank", shape = 18, fill = NA)))+
  ggplot2::theme_minimal()+
  ggplot2::theme(legend.text.align=0.5,
             legend.title.align = 0.5,
             plot.background = element_blank(),
             panel.grid = element_line(colour = "white"),
             panel.background = element_rect(fill = "grey87", color = "white"))+#,
  coord_sf(xlim = c(-68.45,-68.2), ylim = c(-11.05,-10.8))
prod_map_PAECM_fruit_legend_test