在R中绘制行驶路线

Question

我正在遵循这个问题中提供的答案：在 R 中使用传单绘制旅程路径

并希望复制相同的想法：绘制一张显示城市之间驾驶路线的地图。

作为参考，当我简单地复制并粘贴 SymbolixAu 答案中的代码时......效果很好！ （简单的地图，即 googe_map，而不是“闪亮”的代码）。

换句话说，我认为我的 api 密钥设置得很好。但由于某种原因，当我尝试在位置数据上使用相同的代码时，它不起作用。这是我的代码：

df_locations<-structure(list(origin = c("WARWICK", "EAST PROVIDENCE", "WARREN", 
                      "CENTERDALE", "CENTRAL FALLS", "DAVISVILLE", "NORTH PROVIDENCE", 
                      "EAST PROVIDENCE", "PROVIDENCE", "CHEPACHET"), destination = c("CENTERDALE", "EAST PROVIDENCE", "BRISTOL", "JOHNSTON", "CRANSTON", "WARWICK","NORTH PROVIDENCE", "EAST PROVIDENCE", "WARREN", "CHEPACHET")), class = "data.frame", row.names = c(NA, -10L))


## loop over each pair of locations, and extract the polyline from the result
lst_directions <- apply(df_locations, 1, function(x){
res <- google_directions(
key = api_key
, origin = x[['origin']]
, destination = x[['destination']]
)

df_result <- data.frame(
origin = x[['origin']]
, destination = x[['destination']]
, route = res$routes$overview_polyline$points
)
return(df_result)
})

## convert the results to a data.frame
df_directions <- do.call(rbind, lst_directions)

## plot the map
google_map(key = map_key ) %>%
add_polylines(data = df_directions, polyline = "route")

当我进入“apply”循环时，我收到错误“data.frame(origin = x[["origin"]],destination = x[["destination"]], 中的错误： 参数意味着不同的行数：1, 0"

当我重新运行完全相同的代码，但仅使用示例数据框时：

df_locations <- data.frame(
origin = c("Melbourne, Australia", "Sydney, Australia")
, destination = c("Sydney, Australia", "Brisbane, Australia")
, stringsAsFactors = F
)

效果很好。有任何想法吗？我想知道是否因为我的位置只有城市名称（没有州或国家），所以我将示例数据调整为仅说“墨尔本”或“悉尼”，仍然有效。

Answer 1

不管怎样，我只是运行了你的代码，没有任何问题。因此，@Dave2e 怀疑您的 API 调用可能有问题，要么是超时，要么是 google 由于某种原因没有返回结果。因此，您必须继续调试/打印结果，看看是否是这种情况。

df_locations<-structure(list(origin = c("WARWICK", "EAST PROVIDENCE", "WARREN", 
                                        "CENTERDALE", "CENTRAL FALLS", "DAVISVILLE", "NORTH PROVIDENCE", 
                                        "EAST PROVIDENCE", "PROVIDENCE", "CHEPACHET"), destination = c("CENTERDALE", "EAST PROVIDENCE", "BRISTOL", "JOHNSTON", "CRANSTON", "WARWICK","NORTH PROVIDENCE", "EAST PROVIDENCE", "WARREN", "CHEPACHET")), class = "data.frame", row.names = c(NA, -10L))

library(googleway)

set_key("MYKEY")


## loop over each pair of locations, and extract the polyline from the result
lst_directions <- apply(df_locations, 1, function(x){
  res <- google_directions(
    origin = x[['origin']]
    , destination = x[['destination']]
  )

  df_result <- data.frame(
    origin = x[['origin']]
    , destination = x[['destination']]
    , route = res$routes$overview_polyline$points
  )
  return(df_result)
})

df_directions <- do.call(rbind, lst_directions)

## plot the map
google_map() %>%
  add_polylines(data = df_directions, polyline = "route")

Answer 2

如果将函数分成两部分，则更容易看到错误。

    lst_directions <- apply(df_locations, 1, function(x){
    res <- google_directions(
      origin = x[['origin']], 
      destination = x[['destination']]
  )
})

结果会创建一个列表，您可以看到哪些地理编码失败。例如，当我运行时，出现以下错误。

lst_directions[[1]]

$geocoded_waypoints
  geocoder_status                    place_id               types
1    ZERO_RESULTS                        <NA>                NULL
2              OK ChIJfbgEZoJG5IkRezxu2nfHggk locality, political

$routes
list()

$status
[1] "NOT_FOUND"

有效的输出如下

lst_directions[[2]]

$geocoded_waypoints
  geocoder_status                    place_id               types
1              OK ChIJNYT8S5ha5IkRgDDkgjwJHgc locality, political
2              OK ChIJNYT8S5ha5IkRgDDkgjwJHgc locality, political

$routes
  bounds.northeast.lat bounds.northeast.lng bounds.southwest.lat bounds.southwest.lng            copyrights
1             41.81361            -71.37006             41.81361            -71.37006 Map data ©2024 Google
                                                                                                                                                                                                                                        legs
1 1 m, 0, 1 min, 0, East Providence, RI, USA, 41.8136127, -71.3700603, East Providence, RI, USA, 41.8136127, -71.3700603, 1 m, 0, 1 min, 0, 41.8136127, -71.3700603, Head on <b>Warren Ave</b>, ave~FzmrrL, 41.8136127, -71.3700603, DRIVING
      points    summary warnings waypoint_order
1 ave~FzmrrL Warren Ave     NULL           NULL

$status
[1] "OK"

仍然可能是建议的地理编码问题，但至少这有助于调试。