读取数据
#加载包
library(sf) #读取矢量数据
library(rgdal)#投影问题
library(ggplot2)#主要作图
library(maptools)
library(mapproj)#投影
library(ggsn)#指北针和比例尺
library(readxl) #读取表格数据
library(ggspatial) #构建比例尺和指北针
library(showtext) #解决没有办法提取出来的中文图例
library(Cairo) #解决没有办法提取出来的中文图例
library(classInt)#调色板
options(scipen = 200) # 科学计数法取消
showtext_auto(enable = T) #显示中文图例
jiangsu<- st_read("D:/R/各省矢量地图/江苏.shp")
tab_jiangsu <- read_xlsx("C:/Users/mingxu/Desktop/中药资源区划示例数据/江苏.xlsx")
jiangsu_join <- dplyr::left_join(tab_jiangsu, jiangsu, by = c("县代码" = "PAC")) 
# 种植面积
ggplot(data = jiangsu_join)+  
  geom_sf(aes(fill = `种植面积(万亩)`, geometry = `geometry`,),color="grey50")+
  scale_fill_continuous(low="green",high="firebrick1",na.value = "white",breaks =c(5,15,25,35))+
  annotation_scale(location='bl') +                                      
  coord_sf(crs=4326)+                                                     
  annotation_north_arrow(location='tr',which_north='false',style=north_arrow_fancy_orienteering())+
  theme(axis.text = element_blank(),panel.background = element_blank(),panel.grid=element_blank(),axis.ticks=element_blank())
ggsave("江苏药材面积分级图3.eps",device = cairo_pdf,path = "C:/Users/mingxu/Desktop/示例储存")