R从空间点数据帧到空间线

我有一个空间点数据帧加载

pst<-readOGR("/data_spatial/coast/","points_coast")

---

pst我已经查看了shapefile。有一个
id
列，但是如果您绘制数据，则该id似乎不是按南北顺序排列的。创建额外的线是因为点顺序不完美，连接表中彼此相邻但在空间上彼此相距较远的点。您可以通过计算点之间的距离，然后按距离排序，尝试找出数据的正确顺序

解决方法是移除超过一定距离（例如500米）的管线。。首先，找出连续坐标之间的距离大于此距离的位置：
中断。然后取两个
断点之间的坐标子集，最后为该子集创建线。最终得到的海岸线由几个（
breaks-1
）段组成，没有错误的段

# read data
library(rgdal)
pst<-readOGR("/data_spatial/coast/","points_coast")
coord<-as.data.frame(coordinates(pst))
colnames(coord) <- c('X','Y')

# determine distance between consective coordinates
linelength = LineLength(as.matrix(coord),sum=F)
# 'id' of long lines, plus first and last item of dataset
breaks = c(1,which(linelength>500),nrow(coord))

# check position of breaks
breaks = c(1,which(linelength>500),nrow(coord))

# plot extent of coords and check breaks
plot(coord,type='n')
points(coord[breaks,], pch=16,cex=1)

# create vector to be filled with lines of each subset
ll <- vector("list", length(breaks)-1)
for (i in 1: (length(breaks)-1)){
    subcoord = coord[(breaks[i]+1):(breaks[i+1]),]

# check if subset contains more than 2 coordinates
    if (nrow(subcoord) >= 2){
        Slo1<-Line(subcoord)
        Sli1<-Lines(list(Slo1),ID=paste0('section',i))
        ll[[i]] = Sli1
    }

}

# remove any invalid lines
nulls = which(unlist(lapply(ll,is.null)))
ll = ll[-nulls]
lin = SpatialLines(ll)
# add result to plot
lines(lin,col=2)

# write shapefile
df = data.frame(row.names=names(lin),id=1:length(names(lin)))
lin2 = SpatialLinesDataFrame(sl=lin, data=df)
proj4string(lin2) <- proj4string(pst)
writeOGR(obj=lin2, layer='coastline', dsn='/data_spatial/coast', driver='ESRI Shapefile')

#读取数据
图书馆（rgdal）
pstI看到文件“points_coast.zip”，但不知道如何下载它。你点击什么下载文件？有多少行？这些要点需要组织起来，而不仅仅是串在一起。是否有指定线路ID和/或线路内订购点的属性？若要下载，请单击
valider et telechargez le fichier
。感谢koekenbakker提供的小指南：-）。@萨姆纳：我想要一行。。。但我的分数超过了4000分。/谢谢koekenbakker！！真是太棒了！一个小问题。。。我怎样才能写GR？
# read data
library(rgdal)
pst<-readOGR("/data_spatial/coast/","points_coast")
coord<-as.data.frame(coordinates(pst))
colnames(coord) <- c('X','Y')

# determine distance between consective coordinates
linelength = LineLength(as.matrix(coord),sum=F)
# 'id' of long lines, plus first and last item of dataset
breaks = c(1,which(linelength>500),nrow(coord))

# check position of breaks
breaks = c(1,which(linelength>500),nrow(coord))

# plot extent of coords and check breaks
plot(coord,type='n')
points(coord[breaks,], pch=16,cex=1)

# create vector to be filled with lines of each subset
ll <- vector("list", length(breaks)-1)
for (i in 1: (length(breaks)-1)){
    subcoord = coord[(breaks[i]+1):(breaks[i+1]),]

# check if subset contains more than 2 coordinates
    if (nrow(subcoord) >= 2){
        Slo1<-Line(subcoord)
        Sli1<-Lines(list(Slo1),ID=paste0('section',i))
        ll[[i]] = Sli1
    }

}

# remove any invalid lines
nulls = which(unlist(lapply(ll,is.null)))
ll = ll[-nulls]
lin = SpatialLines(ll)
# add result to plot
lines(lin,col=2)

# write shapefile
df = data.frame(row.names=names(lin),id=1:length(names(lin)))
lin2 = SpatialLinesDataFrame(sl=lin, data=df)
proj4string(lin2) <- proj4string(pst)
writeOGR(obj=lin2, layer='coastline', dsn='/data_spatial/coast', driver='ESRI Shapefile')