使用 R 将 SpatialPoints 与 SpatialLines 匹配/连接

Question

我有一个一组 shapefile https://www.dropbox.com/sh/ujoq4nb6tguv9kf/AAAzL-1-Mph-A4duvnKK33aDa?dl=0前往开罗的不同巴士路线（每条路线有 2 趟车次）。我想用 R 检查他们是否经过某些车站：

Stops_Data <- readOGR("Stackoverflow Data/","Stops_Data")
Trips_Data <- readOGR("Stackoverflow Data/","Trips_Data")

plot(Trips_Data)
points(Stops_Data,  col = "red")

我尝试使用 over() 来匹配它们。首先，我确保投影是相同的。

proj4string(Trips_Data) <- proj4string(Stops_Data)
over(Stops_Data, Trips_Data)

这仅给出 NA。

所需输出

目标是获取一个将每个行程与其经过的停靠点相匹配的表，并使用以下形式创建一个表：

      trip_id      stop_id stop_name stop_seque
45 CTA_1021_O PaM_1031_EMB    Embaba          1
46 CTA_1021_O PaM_1039_KKT   Kit Kat          2
47 CTA_1021_O PaM_1009_AGZ    Agouza          3
48 CTA_1021_O PaM_2004_ISA     Isaaf          4
49 CTA_1021_O PaM_1059_RAM    Ramses          5
50 CTA_1021_O PaM_1035_GMR    Ghamra          6

可能的解决方案？

我什至不相信将点与线匹配是可能的，因为坐标几乎总是会有轻微的偏差。线条不像多边形那样有余地。

因此，我在想有没有办法将 SpatialLinesDataFrame 转换为多边形？考虑围绕每条公交路线制作一个宽度为 100m 的多边形，从而自然地包含所有站点。

如果“100m”值是近的定义，那么我们可以使用rgeos::gDistance()但我们需要将空间对象重新投影到以米与度为单位的投影：

library(rgdal)
library(rgeos)
library(sp)
library(dplyr)
library(tidyr)

route_stops <- readOGR("Stops_Data.shp", "Stops_Data", stringsAsFactors=FALSE)
c <- readOGR("Trips_Data.shp", "Trips_Data", stringsAsFactors=FALSE)

# need meters vs degrees
prj <- "+proj=aea +lat_1=29.9 +lat_2=30.2 +lon_0=30.9"

route_stops <- SpatialPointsDataFrame(spTransform(route_stops, CRS(prj)), route_stops@data)
trips <- SpatialLinesDataFrame(spTransform(trips, CRS(prj)), trips@data)

# get a bird's eye view
plot(trips)
plot(route_stops, add=TRUE)

现在，我们将查看哪些点在 100m 之内：

near <- suppressWarnings(gDistance(route_stops, trips, byid=TRUE))
near <- apply(near, 1, `<=`, 100)

# make it easier to work with later on and include other data elements
colnames(near) <- trips$route_id
near <- data.frame(near)
near$stop_id <- route_stops$stop_id
near$stop_name <- route_stops$stop_name

# see what we found
plot(trips)
plot(route_stops[apply(near[,1:4], 1, any),], add=TRUE)

现在，我们只需要按路线查看点，因此我们进行一些数据整理，然后添加序列 # （这可能是错误的，因为我不知道点是否按顺序排列，因此您可以卷起袖子对于这一点）：

gather(near, route, stop, -stop_id, -stop_name) %>% 
  group_by(route) %>% 
  filter(stop) %>% 
  mutate(stop_seq=1:n()) %>% 
  select(trip_id=route, stop_id, stop_name, stop_seq, -stop) %>% 
  ungroup() -> desired_output

print(desired_output, n=44)

## Source: local data frame [44 x 4]
## 
##       trip_id      stop_id                    stop_name stop_seq
##         <chr>        <chr>                        <chr>    <int>
## 1    CTA_1021 PaM_1059_RAM                       Ramses        1
## 2    CTA_1021 PaM_1035_GMR                       Ghamra        2
## 3    CTA_1021 PaM_1064_ZAM                      Zamalek        3
## 4    CTA_1021 PaM_1054_MUN               Mustafa Nahhas        4
## 5    CTA_1021 PaM_1064_SSS               Salah Salem St        5
## 6    CTA_1021 PaM_1057_RAB             Rabaa El-Adaweya        6
## 7    CTA_1021 PaM_1030_TAY                    Eltayaran        7
## 8    CTA_1021 PaM_1004_EIT                 8th District        8
## 9    CTA_1021 PaM_1048_MNH                       Manhal        9
## 10   CTA_1021 PaM_1031_EMB                       Embaba       10
## 11   CTA_1021 PaM_1039_KKT                      Kit Kat       11
## 12   CTA_1021 PaM_1073_TAB                        Tabba       12
## 13   CTA_1021 PaM_1043_MAA                       Ma3rad       13
## 14   CTA_1021 PaM_1072_TAS                 Ta'men Sehhy       14
## 15   CTA_1021 PaM_2004_ISA                        Isaaf       15
## 16   CTA_1020 PaM_1042_LEB               Lebanon Square        1
## 17   CTA_1020 PaM_1059_RAM                       Ramses        2
## 18   CTA_1020 PaM_1007_ART Abdel el Monem Riad / Tahrir        3
## 19   CTA_1020 PaM_1070_SFX                Sphinx Square        4
## 20   CTA_1020 PaM_1009_AGZ                       Agouza        5
## 21   CTA_1020 PaM_2004_ISA                        Isaaf        6
## 22   CTA_1020 PaM_2005_AHM                  Ahmed Helmy        7
## 23 CTA_1021.1 PaM_1059_RAM                       Ramses        1
## 24 CTA_1021.1 PaM_1035_GMR                       Ghamra        2
## 25 CTA_1021.1 PaM_1064_ZAM                      Zamalek        3
## 26 CTA_1021.1 PaM_1054_MUN               Mustafa Nahhas        4
## 27 CTA_1021.1 PaM_1064_SSS               Salah Salem St        5
## 28 CTA_1021.1 PaM_1057_RAB             Rabaa El-Adaweya        6
## 29 CTA_1021.1 PaM_1030_TAY                    Eltayaran        7
## 30 CTA_1021.1 PaM_1004_EIT                 8th District        8
## 31 CTA_1021.1 PaM_1048_MNH                       Manhal        9
## 32 CTA_1021.1 PaM_1031_EMB                       Embaba       10
## 33 CTA_1021.1 PaM_1039_KKT                      Kit Kat       11
## 34 CTA_1021.1 PaM_1073_TAB                        Tabba       12
## 35 CTA_1021.1 PaM_1043_MAA                       Ma3rad       13
## 36 CTA_1021.1 PaM_1072_TAS                 Ta'men Sehhy       14
## 37 CTA_1021.1 PaM_2004_ISA                        Isaaf       15
## 38 CTA_1020.1 PaM_1042_LEB               Lebanon Square        1
## 39 CTA_1020.1 PaM_1059_RAM                       Ramses        2
## 40 CTA_1020.1 PaM_1007_ART Abdel el Monem Riad / Tahrir        3
## 41 CTA_1020.1 PaM_1070_SFX                Sphinx Square        4
## 42 CTA_1020.1 PaM_1009_AGZ                       Agouza        5
## 43 CTA_1020.1 PaM_2004_ISA                        Isaaf        6
## 44 CTA_1020.1 PaM_2005_AHM                  Ahmed Helmy        7