R 使用sf将线串拆分为多线串

我试图在一个数据帧中以“LINESTRING”sf格式拆分两行，在另一个数据帧中以“MULTIPOLYGON”sf格式拆分两个圆圈

# make data frame with sf points 
lndf <- data.frame(
  x = c(40, 55, 60, 70),
  y = c(5, 20, 30, 35),
  attr_data = c(10,10,10,10),
  var = c("abc", "abc", "bac", "bac")
) %>% # convert longitude and latitude into sf points with crs
  st_as_sf(coords = c("x","y"), dim = "XY") %>% 
  st_set_crs(4326)

# convert sf points to sf lines -> first dataframe
lndf <- lndf %>% 
  group_by(var) %>% 
  summarize(a = sum(attr_data)) %>%         
  st_cast("LINESTRING")

# make data frame with sf points
cidf <- data.frame(
  x = c(40, 55, 60, 70),
  y = c(5, 20, 30, 35),
  attr_data = c(10,10,10,10),
  gr = c("abc", "abc", "bac", "bac")
) %>% # convert longitude and latitude into sf points with crs
  st_as_sf(coords = c("x","y"), dim = "XY") %>% 
  st_set_crs(4326)

# convert sf points to sf circle polygons 
cidf <- st_buffer(cidf, 1)   

# convert sf circle polygons to sf multilinestring  -> second dataframe
mls_cidf <- cidf %>% 
  group_by(gr) %>% 
  summarize(a = sum(attr_data)) %>%     
  st_cast("MULTILINESTRING", group_or_split = FALSE) %>% 
  st_set_crs(4326)

# Calculating intersection points between lines and circle polygons
inters <- st_intersection(lndf$geometry, mls_cidf)

# Calculating small circles around intersection points
buffer <- st_buffer(inters, dist = 1e-12)

# split linestring into multilinestring
difference <- st_difference(lndf, buffer) 

#使用sf点制作数据帧
lndf%#使用crs将经度和纬度转换为sf点
st_as_sf（coords=c（“x”，“y”），dim=“XY”）%>%
st_集_crs（4326）
#将sf点转换为sf线->第一个数据帧
lndf%
分组依据（var）%>%
汇总（a=总和（属性数据））%>%
st_铸造（“线串”）
#使用sf点制作数据帧
cidf%#使用crs将经度和纬度转换为sf点
st_as_sf（coords=c（“x”，“y”），dim=“XY”）%>%
st_集_crs（4326）
#将sf点转换为sf圆多边形
第二数据帧
mls_cidf%
分组依据（gr）%>%
汇总（a=总和（属性数据））%>%
st_cast（“多重约束”，组或分割=假）%>%
st_集_crs（4326）
#计算直线和圆多边形之间的交点
inters似乎答案包括使用purrr:：map2

# split linestring into multilinestring  
mls_to_ls <- function(ls, pl) {
  st_difference(ls, st_buffer(st_intersection(ls, pl), dist = 1e-12))
}
# iterate over rows of lndf and mls_cidf
map2(lndf$geometry, mls_cidf$geometry, mls_to_ls)

#将行字符串拆分为多行字符串
mls_to_ls要转换为
sf
data.frame
您需要几个额外的步骤：
sf:：st_sf（geometry=sf:：st_sfc（purr:：map2（lndf$geometry，mls_cidf$geometry，mls_to_ls））
# split linestring into multilinestring  
mls_to_ls <- function(ls, pl) {
  st_difference(ls, st_buffer(st_intersection(ls, pl), dist = 1e-12))
}
# iterate over rows of lndf and mls_cidf
map2(lndf$geometry, mls_cidf$geometry, mls_to_ls)