[OSRM-talk] Plotting position in time using OSRM
S R
sriram_ott at yahoo.com
Wed Dec 3 17:58:41 UTC 2014
Thanks Carsten...I understand a bit better now..
By the way, I am not clear where I should be looking for the AJAX response (to see the via_point values and route_instructions) in firebug output...can you provide some guidance? I see the firebug output at the bottom of the map...
I will ignore the via_indices as you pointed out there may be errors with it.
And I guess interpolation using the azimuth? would work?
Regards
Sriram
From: Carsten Malchow <carsten64stadt at gmx.de>
To: osrm-talk at openstreetmap.org
Sent: Wednesday, December 3, 2014 12:35 PM
Subject: Re: [OSRM-talk] Plotting position in time using OSRM
Please look at this exampleand open firebug to see the JSON response.here I add a Way point. there you see that the via_point has 3 elements as also the via_indices, but this via_indices not corrosponed to any numbers in the route_instruction.If you reach the way point then in the route instruction the driving directions contains the number 9, for the start points is 10 and for the end point is 15. Also you start from a point and all information you have is related to the next point. Means for example your startpoint contains an entry of 200m means that in 200m the next point is coming. osrm.at/ag6 I hope I could example this clearly now. According to you b.) question may be interpolation would help, becouse you have only route instructions if a bigger change in the direction will occure.reagardsCGesendet: Mittwoch, 03. Dezember 2014 um 12:20 Uhr
Von: "S R" <sriram_ott at yahoo.com>
An: "Mailing list to discuss Project OSRM" <osrm-talk at openstreetmap.org>
Betreff: Re: [OSRM-talk] Plotting position in time using OSRM
Thanks Carsten. To clarify then: a. if position is 4, i can find the location of the corresponding start point using via_point[4]. This does not seem correct though when I look at the example API (Requesting Routes section): https://github.com/Project-OSRM/osrm-backend/wiki/Server-api In that case there is only start and end, but the route_instructions array has 6 elements. The position values of these 6 elements are 0, 2, 3, 8, 17, 20. The via_points array has only 2 elements. So it is not clear how to interpret the "position" attribute. b. I realize now that the travel times is the time for travel to the next via point. That is why the end point has a travel time of 0. It is still unclear of course how I can figure out the lat+long of position along a street. ThanksSriram From: Carsten Malchow <carsten64stadt at gmx.de>
To: osrm-talk at openstreetmap.org
Sent: Wednesday, December 3, 2014 11:49 AM
Subject: Re: [OSRM-talk] Plotting position in time using OSRM Hi, ["Turn left", "High Street", 200, /// yes this is Integer in the unit of meters from the last instruction 4, // Posistion of instructions according to the geomerty and of course to the start point // dont be scared if this number not follwong the ristrict order if of 3 not follwos 4. // as I understand this correct this occur because of a generalizaion of the raw geomerty, with this some points can be eliminate. 10, //Travel time to this point from the last instructions "200m", "NE", 22.5 ]1.)via_points just give the coordinates back of start/end and intermieat pointsvia_indices look this: https://github.com/Project-OSRM/osrm-backend/issues/1020 2.) I think this you have to calculated by your self. regards CarstenGesendet: Mittwoch, 03. Dezember 2014 um 11:04 Uhr
Von: "S R" <sriram_ott at yahoo.com>
An: "Mailing list to discuss Project OSRM" <osrm-talk at openstreetmap.org>
Betreff: Re: [OSRM-talk] Plotting position in time using OSRM
Hi Carsten Many thanks....the link you mention shows the route instructions describe each street and gives the position of the start point, its length, and time in seconds. This is very helpful. Still the documentation is not fully clear (to me). Take the example in the link: ["Turn left", "High Street", 200, <------ 200 m long 4, <------ position (of the starting point on the street?) 10, <------- time to traverse this street? "200m", "NE", 22.5 ] My questions are: 1. What is the lat/long of the starting position on High Street i.e how to convert "4" to lat/long. I think this has to do with via indices and via points in the link you mention, but that seems a bit murky (at least to me). Any clarification would help a lot. What is the difference between via_indices and via_points. Is there a via_point for each point in the route instruction? Can I just use one or the other? 2. After say 5 seconds of travel on High Street, what would be the lat/long of the new position. ThanksSriram From: Carsten Malchow <carsten64stadt at gmx.de>
To: osrm-talk at openstreetmap.org
Sent: Wednesday, December 3, 2014 10:43 AM
Subject: Re: [OSRM-talk] Plotting position in time using OSRM Hi Sriram to reply a part of your question:take a look at this documentacion [1]The first number is driving directions.The geomerty is a compressed tring that you have to decompress.also discripted in the Link below. Kind regards Carsten [1] https://github.com/Project-OSRM/osrm-backend/wiki/Output-jsonGesendet: Mittwoch, 03. Dezember 2014 um 09:58 Uhr
Von: "S R" <sriram_ott at yahoo.com>
An: "osrm-talk at openstreetmap.org" <osrm-talk at openstreetmap.org>
Betreff: [OSRM-talk] Plotting position in time using OSRM
I would like to create a simple simulation of a trip using OSRM. I believe the steps would be as follows (my questions are in parenthesis below) a. Load OSM map of a city into OSRMb. Choose a random begin, end location that falls within the city lat/long (how to find lat/long limits of the loaded map?)c. Compute the distance (in time) between start, end using OSRMd. Also compute a path between start, end using OSRM (are the node vertices mentioned in route the same as in the OSM map?)e. The difficult part: -- start the simulation by displaying the map along with position marker (Leaflet?) -- As time progresses, determine the location along the OSRM route computed above (how can this be done?) and adjust the position marker. An OSRM route looks like this:"route_instructions": [
[
"10", <-------------------- what is this id and how to convert it to lat/long
"Schulstraße",
126,
0,
18,
"126m",
"SE",
116
],
[
"7", <---------------- how to find elapsed time to this point from previous one
"Am Rahmtor",
57,
2,
11,
"57m",
"NE",
38
]
Given a start and end lat/long, a network distance (time) can be obtained as follows:
"distance_table": [
[
0,
26084
],
[
26084,
0
]
This would be useful if the route way-points above could be converted into time units.
Would appreciate any help with the above questions,Sriram_______________________________________________ OSRM-talk mailing list OSRM-talk at openstreetmap.org https://lists.openstreetmap.org/listinfo/osrm-talk _______________________________________________
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