计算路线：(列表)对象不能被强制输入'double‘

Question

我有一个开始和结束坐标的df。我试着计算出df的一小部分，大约300次行程的全程。ggmap路由函数开始运行，但在大约12次路由计算后出现错误。错误是(列表)对象不能强制输入'double'。我如何在代码中解决这个问题？我有一个csv的数据在下面的链接，供任何人测试。

总体的最终目标是像这个http://flowingdata.com/2014/02/05/where-people-run/这样的产品，可视化所有的路线。

library(tidyverse)
library(ggmap)
feb_14 <- read.csv('https://raw.githubusercontent.com/smitty1788/Personal-Website/master/dl/CaBi_Feb_2017.csv', stringsAsFactors = FALSE)


start<-c(feb_14[1:300, 14])
dest<-c(feb_14[1:300, 15])


routes <- tibble(
  start,
  dest)

calculationroute <- function(startingpoint, stoppoint) {
  route(from = startingpoint,
        to = stoppoint,
        mode = 'bicycling',
        structure = "route")}

calculatedroutes <- mapply(calculationroute,
                           startingpoint = routes$start,
                           stoppoint = routes$dest,
                           SIMPLIFY = FALSE)

do.call(rbind.data.frame, lapply(names(calculatedroutes), function(x) {
  cbind.data.frame(route=x, calculatedroutes[[x]], stringsAsFactors=FALSE)
})) -> long_routes

这是错误

Error in route(from = startingpoint, to = stoppoint, mode = "bicycling",  : 
  (list) object cannot be coerced to type 'double'
Called from: route(from = startingpoint, to = stoppoint, mode = "bicycling", 
    structure = "route")
Browse[1]> 
do.call(rbind.data.frame, lapply(names(calculatedroutes), function(x) {
+   cbind.data.frame(route=x, calculatedroutes[[x]], stringsAsFactors=FALSE)
+ })) -> long_routes

Answer 1

错误发生在Google上。我达到了每秒的速率限制。简单的解决方法是添加一个Sys.Sleep来降低呼叫速率。

calculationroute <- function(startingpoint, stoppoint) {
 Sys.sleep(1)
  route(from = startingpoint,
        to = stoppoint,
        mode = "bicycling",
        structure = "route")}