我试图用纬度和经度数据制作一张Map。我能够使用coords_sf()缩放Map上绘制的数据，但当我试图使用annotation_scale()将比例尺添加到geom_plot()时，它并没有像this例子中那样重新组织几何限制。我试图使用geom_sf()和coords_sf()来绘制数据，有相同的结果（2米长的比例尺）。我已经能够添加它与ggsn::scalebar()功能，但我很好奇如何使它使用annotation_scale()工作。提前感谢！请在下面找到我的代码。

library(ggplot2)
library(maps)
library(mapdata)
library(ggpubr)
library(ggspatial)
library(sf)
region <- map_data("world2Hires")  # the basemap polygon, saved in a object called "region"
region <- subset(region, region %in% c('Canada', 'USA')) # break region into Canada and the USA
region$long = (360 - region$long)*-1    # convert lat/lon
# Save Canada and the USA as different objects
Canada <- subset(region, region == 'Canada') # Canada 
USA <- subset(region, region == 'USA')       # USA 
# Set the coordinates of map
lons = c(-68, -59.5)     # (max longitude, min longitude)
lats = c(43, 48)       # (min latitude, max latitude)
# Create the map using ggplot
# the Longitude/Latitude of each circle comes from the CSV files imported in step 2 
study.area <- ggplot() +
  coord_sf(xlim = lons, ylim = lats) +  
  geom_polygon(data = Canada, aes(x = long, y = lat, group = group), colour = "grey20", fill = "grey85") + 
  geom_polygon(data = USA, aes(x = long, y = lat, group = group), colour = "grey20", fill = "grey93") +
  xlab("Longitude") + 
  ylab("Latitude") + 
  theme_bw() +
  theme(panel.grid.minor = element_blank(),
        panel.grid.major = element_blank(),
        panel.background = element_blank(),
        axis.text = element_text(size = 11),
        axis.title = element_text(size = 12)) +
  theme(plot.margin = unit(c(0.5,0.5,0.2,0.3), "cm")) +
  #geom_point(data = mydata, aes(long, lat, fill=type), colour="black", pch=21) (this is my data plotted as points which I commented out for the sake of the example set)
  labs(shape = "year") +
  geom_jitter() +
  annotation_scale()
study.area

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