Snapped distance not being calculated as crow flies "walking" distance

[Mponkane]

Brief description of the problem:

When origin is snapped to network, it does not account for the crow flies distance from the original location. See picture below.

both origin and destination are in WGS 84

here is the ttm result:
from_id to_id travel_time_p50
1: origin destination 0

here is find_snap for origin:
point_id, lat, lon, snap_lat, snap_lon, distance, found
1: origin, 65.05129, 25.42877, 65.04899, 25.42855, 255.8379, TRUE

here is find_snap for destination:
point_id, lat, lon, snap_lat, snap_lon, distance, found
1: destination, 65.04884, 25.42872, 65.04883, 25.42872, 1.176363, TRUE

Reproducible example here

options(java.parameters = "-Xmx20G")
library(r5r)
library(sf)
library(dplyr)
library(ggplot2)

  
r5r_core <- setup_r5("path")
origin <- st_read("test_origin.gpkg")
destination <- st_read("test_dest.gpkg")


det <- detailed_itineraries(
  r5r_core,
  origins = origin,
  destinations = destination,
  mode = "BICYCLE",
  max_trip_duration = 30,
  max_lts = 2,
  bike_speed = 15,
  walk_speed = 2,
  shortest_path = TRUE,
  all_to_all = TRUE
)

ttm <- travel_time_matrix(
  r5r_core,
  origins = origin,
  destinations = destination,
  mode = "BICYCLE",
  max_trip_duration = 30,
  max_lts = 2,
  bike_speed = 15,
  walk_speed = 2
)

snap_df <- find_snap(r5r_core, origin, mode = "BICYCLE")

Situation report

$r5r_package_version
[1] ‘1.1.0’

$r5_jar_version
[1] "6.9"

$java_version
[1] "11.0.18"

$set_memory
[1] "-Xmx20G"

$session_info
R version 4.2.2 (2022-10-31 ucrt)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 22631)

Matrix products: default

locale:
[1] LC_COLLATE=English_Finland.utf8 LC_CTYPE=English_Finland.utf8 LC_MONETARY=English_Finland.utf8 LC_NUMERIC=C
[5] LC_TIME=English_Finland.utf8

attached base packages:
[1] stats graphics grDevices utils datasets methods base

other attached packages:
[1] readr_2.1.4 ggplot2_3.4.4 r5r_1.1.0 dplyr_1.1.3 sf_1.0-14

loaded via a namespace (and not attached):
[1] Rcpp_1.0.11 pillar_1.9.0 compiler_4.2.2 class_7.3-20 tools_4.2.2 bit_4.0.5 lifecycle_1.0.4
[8] tibble_3.2.1 gtable_0.3.4 checkmate_2.3.1 pkgconfig_2.0.3 rlang_1.1.1 DBI_1.1.3 cli_3.6.0
[15] rstudioapi_0.15.0 parallel_4.2.2 rJava_1.0-10 e1071_1.7-14 withr_2.5.2 sfheaders_0.4.3 generics_0.1.3
[22] vctrs_0.6.4 hms_1.1.3 bit64_4.0.5 classInt_0.4-10 grid_4.2.2 tidyselect_1.2.0 glue_1.6.2
[29] data.table_1.14.6 R6_2.5.1 fansi_1.0.4 vroom_1.6.5 tzdb_0.4.0 magrittr_2.0.3 backports_1.4.1
[36] scales_1.3.0 units_0.8-5 colorspace_2.1-0 utf8_1.2.2 KernSmooth_2.23-20 proxy_0.4-27 munsell_0.5.0
[43] crayon_1.5.2

[rafapereirabr]

You've set a cycling speed of 15 km/h. That's aprox 250 meters per minute, so this might be a rounding issue.
What happens if you set a lower speed? Or walking mode ?

[Mponkane]

Hi,

The result is the same for walking mode / slower cycling speeds. Also if I increase the distance of the origin point from the network up to 1.6 km.

[rafapereirabr]

Thanks for the quick reply!
Ok, in this case this seems to be an issue upstream on R5. Would mind reporting this to them opening an issue on their github repo.

[rafapereirabr]

Related to #277