所以我正在使用数据框运行一些驱动时间（我只发布前27行的子集），如下所示：
h_postcode gp_postcode
CV2 2DX YO31 7WE
CV2 2DX LL57 2HH
CV2 2DX TR8 4HP
CV2 2DX YO25 6EB
CV2 2DX SA15 3AE
CV2 2DX B63 1AB
CV2 2DX SN1 1ED
CV2 2DX YO32 2LL
CV2 2DX OX4 4DH
CV2 2DX HA8 8NB
CV2 2DX NP44 1RY
CV2 2DX CV3 1EG
CV2 2DX CB2 1RG
CV2 2DX SS0 7AF
CV2 2DX S14 1PQ
CV2 2DX DY3 1LS
CV2 2DX NN11 4FE
CV2 2DX CV47 2UL
CV2 2DX CV1 5FX
CV2 2DX CV1 4FS
CV2 2DX PE28 3EU
CV2 2DX B70 0PU
CV2 2DX CV1 4JH
CV2 2DX WR2 5HL
CV2 2DX ST7 4SS
CV2 2DX PL4 7DL
CV2 2DX CV6 6DR
申请我的代码时：
# create your own 'from' and 'to' variables
from <- drivetime$gp_postcode
to <- drivetime$h_postcode
# calculate the distance
result <- vector("list")
for (i in 1:1000) { # could be 1:nrow(drivetime)
result[[i]] <- try(mapdist(from[i], to[i], mode = "driving", override_limit = TRUE), silent = FALSE)
Sys.sleep(1)
}
results <- dput(result)
res_df <- do.call(rbind, results)
res_df
但我已经意识到，有时带有驱动时间结果的结果数据框的显示顺序与初始数据的顺序不同。 例如，看起来前27行不同于最初的27行：
from to m km miles seconds minutes hours
1 NG17 7LG CV2 2DX 93592 93.592 58.15807 3919 65.31667 1.0886111
2 NP20 2LB CV2 2DX 188427 188.427 117.08854 7667 127.78333 2.1297222
3 EX18 7DL CV2 2DX 308160 308.160 191.49062 11817 196.95000 3.2825000
4 HR4 8SN CV2 2DX 144135 144.135 89.56549 7044 117.40000 1.9566667
5 WS11 5JT CV2 2DX 62974 62.974 39.13204 2706 45.10000 0.7516667
6 TR14 8SN CV2 2DX 451326 451.326 280.45398 16343 272.38333 4.5397222
7 B8 3HX CV2 2DX 37435 37.435 23.26211 2145 35.75000 0.5958333
8 MK2 2EH CV2 2DX 82608 82.608 51.33261 3710 61.83333 1.0305556
9 YO8 4QH CV2 2DX 184817 184.817 114.84528 7457 124.28333 2.0713889
10 SL4 6AP CV2 2DX 158368 158.368 98.40988 6100 101.66667 1.6944444
11 BA2 3JZ CV2 2DX 199397 199.397 123.90530 8217 136.95000 2.2825000
12 DA14 4TA CV2 2DX 207877 207.877 129.17477 8159 135.98333 2.2663889
13 SA31 1EX CV2 2DX 310432 310.432 192.90244 11716 195.26667 3.2544444
14 HP21 8TR CV2 2DX 113968 113.968 70.81972 5149 85.81667 1.4302778
15 ST6 6BE CV2 2DX 112320 112.320 69.79565 4406 73.43333 1.2238889
16 LL22 8LJ CV2 2DX 236466 236.466 146.93997 8788 146.46667 2.4411111
17 RG30 6BP CV2 2DX 158082 158.082 98.23215 6458 107.63333 1.7938889
18 WA6 6RX CV2 2DX 170394 170.394 105.88283 6610 110.16667 1.8361111
19 CV4 9PN CV2 2DX 16669 16.669 10.35812 1427 23.78333 0.3963889
20 B9 5EG CV2 2DX 42486 42.486 26.40080 2102 35.03333 0.5838889
21 SY4 2DR CV2 2DX 118635 118.635 73.71979 4865 81.08333 1.3513889
22 DY9 8DJ CV2 2DX 67934 67.934 42.21419 3130 52.16667 0.8694444
23 DA12 2HU CV2 2DX 208016 208.016 129.26114 8207 136.78333 2.2797222
24 IM9 2RQ CV2 2DX 371277 371.277 230.71153 25926 432.10000 7.2016667
25 FY3 7EN CV2 2DX 236367 236.367 146.87845 8931 148.85000 2.4808333
26 M28 1LZ CV2 2DX 179386 179.386 111.47046 6818 113.63333 1.8938889
27 DY1 2BY CV2 2DX 59939 59.939 37.24609 3073 51.21667 0.8536111
28 SL6 8DS CV2 2DX 143042 143.042 88.88630 5676 94.60000 1.5766667
任何关于它为什么会发生的想法？是因为try() - 即使没有显示错误消息吗？
谢谢！