Start point for round trip should be first coordinate

[DEHWall]

Am I right in assuming that the first and last via_points should be the Start and End (being the same) points of a requested \trip url as follows.

Is there a known issue / fix available?

It also affects the order of the route_instructions.

http://osrm:5000/trip?loc=**51.853842,-3.129779**&loc=51.75983,-3.36673&loc=51.63623,-3.95339&loc=51.64771,-4.03711&loc=51.5827,-3.00176&loc=51.48148,-2.52805&loc=51.37876,-2.43739&loc=51.43524,-2.6002&loc=51.56916,-1.80141&loc=51.5523,-1.7864&loc=51.63753,-1.83719&loc=51.90335,-2.07979&loc=**51.853842,-3.129779**
{
"status_message": "Found trips",
"status": 200,
"trips": [
....
"via_points": [
[
51.636239,-3.953348],[
51.582627,-3.001746],[
51.481475,-2.528061],[
51.435281,-2.600249],[
51.37858,-2.437094],[
51.552301,-1.7864],[
51.569181,-1.801448],[
51.63735,-1.837459],[
51.903344,-2.079795],[
* 51.854382,-3.12917],[ <-------
51.854382,-3.12917],[ <-----*
51.759672,-3.366476],[
51.647716,-4.037114],[
51.636239,-3.953348]],
"permutation": [
2,4,5,7,6,9,8,10,11,0,12,1,3],

Many thanks
Dave

[TheMarex]

@DEHWall omit the last location entry, all trips are planned as round-trips automatically.

[DEHWall]

Still does not do as expected - am I misunderstanding the functionality here?

Given that the starting point is 51.853842,-3.129779

SelectedStops:
0 51.853842,-3.129779
1 51.78524,-3.87921
2 51.66592,-3.30539
3 51.78099,-3.24361
4 51.6192,-3.93939

http://osrm:5000/trip?loc=51.853842,-3.129779&loc=51.78524,-3.87921&loc=51.66592,-3.30539&loc=51.78099,-3.24361&loc=51.6192,-3.93939

Nearest (replot points osrm/nearest)
0 51.854382,-3.12917
1 51.785243,-3.879195
2 51.665925,-3.305397
3 51.780753,-3.243968
4 51.61924,-3.939364

{
"status_message": "Found trips",
"status": 200,
"trips": [
....
"via_points": [
[
51.61924,-3.939364],[ <--- this is not the first parameter
51.785243,-3.879195],[
51.854382,-3.12917],[ <--- would expect this to be first in permutation and First and last in via_points
51.780753,-3.243968],[
51.665925,-3.305397],[
51.61924,-3.939364]], <--- this is not the first parameter
"permutation": [
4,1,0,3,2], <--- and the permutation to be 0,3,2,4,1

[daniel-j-h]

/cc @chaupow

[TheMarex]

@DEHWall yeah the lack of normalization here might be a problem. As a work around just start reading the permutation array at the position of 0 and read with wrap-around (yielding your array). You can feed the result again in viaroute to get a round trip starting at 0.

[DEHWall]

Moving the required Start / End point to the end of the parameter list rather than the first gives a more desired result:

http://osrm:5000/trip?loc=52.45773,-1.87&loc=52.47613,-1.89509&loc=52.58671,-2.00438&loc=52.4785,-1.96992&loc=52.55478,-2.02305&loc=52.45475,-1.87742&loc=52.5158,-1.90405&loc=51.853842,-3.129779

Nearest
52.457734,-1.869988
52.47649,-1.895337
52.586557,-2.004423
52.478502,-1.96994
52.554781,-2.02304
52.454753,-1.877445
52.515769,-1.904067
51.854382,-3.12917 <--- Start and End
{
"status_message": "Found trips",
"status": 200,
"trips": [
...
"via_points": [
[
51.854382,-3.12917],[ <--- Start
52.554781,-2.02304],[
52.586557,-2.004423],[
52.515769,-1.904067],[
52.47649,-1.895337],[
52.457734,-1.869988],[
52.454753,-1.877445],[
52.478502,-1.96994],[
51.854382,-3.12917]], <--- Same as End
"permutation": [ 7,4,2,6,1,0,5,3], <--- In the right sequence

[TheMarex]

The actual problem is not fixed: Trip should start at first coordinate.

[chaupow]

@DEHWall sorry for being late in the convo and thanks for flagging this :) working on it

[chaupow]

@DEHWall just to keep you updated, it was implemented in #3660
and is now waiting for #3408 to get merged into master

edit:
in case you need it earlier, these two lines in src/engine/plugins/trip.cpp are what you want:

auto start_index = std::find(scc_route.begin(), scc_route.end(), 0);
std::rotate(scc_route.begin(), start_index, scc_route.end());

[daniel-j-h]

This landed by now in both the backend and in the node bindings.

You can now request a roundtrip or not (return to the start or not) and fix start and end.