Routing distance between matched points

[RobKoch]

First of all, this library is amazing! Thanks so much for providing us with such great work.

Is there any simple way to include the routing distance between two matched points in the debug output (e.g. by changing the source code)? To make my point clear, I'd like to give an example. For instance, the following JSON sample shows two matched points for two given GPS points. I'd like to include the routing distance between POINT (9.37383970739068 47.429504725440154) and POINT (9.373731696208619 47.429421380914064).

I'm thankful for any advice!

{
    "id": "bad25e18-4fb8-4874-9561-c8a3ac02081b",
    "point": {
      "road": 374570,
      "heading": "forward",
      "frac": 0.038874758720377
    },
    "time": 1457954691,
    "road_edge": 749140,
    "seqprob": -2.5891656830773,
    "geom": "LINESTRING (9.3738989 47.4295504, 9.3738989 47.4295504, 9.37383970739068 47.429504725440154)",
    "transition": {
      "route": {
        "source": {
          "road": 374570,
          "heading": "backward",
          "frac": 1
        },
        "target": {
          "road": 374570,
          "heading": "forward",
          "frac": 0.038874758720377
        },
        "roads": [
          {
            "road": 374570,
            "heading": "backward"
          },
          {
            "road": 374570,
            "heading": "forward"
          }
        ]
      }
    },
    "point_matched": "POINT (9.37383970739068 47.429504725440154)",
    "filtprob": 0.31211030877409,
    "frac": 0.038874758720377
  },
  {
    "id": "90b458bf-de66-4a6e-8675-7b38904a212a",
    "point": {
      "road": 374570,
      "heading": "forward",
      "frac": 0.10981129879372
    },
    "time": 1457954692,
    "road_edge": 749140,
    "seqprob": -4.2432779916644,
    "geom": "LINESTRING (9.37383970739068 47.429504725440154, 9.373731696208619 47.429421380914064)",
    "transition": {
      "route": {
        "source": {
          "road": 374570,
          "heading": "forward",
          "frac": 0.038874758720377
        },
        "target": {
          "road": 374570,
          "heading": "forward",
          "frac": 0.10981129879372
        },
        "roads": [
          {
            "road": 374570,
            "heading": "forward"
          }
        ]
      }
    },
    "point_matched": "POINT (9.373731696208619 47.429421380914064)",
    "filtprob": 0.40308485166153,
    "frac": 0.10981129879372
  }

[smattheis]

Thanks for the kind words. You have mutliple options:

1. In the MatcherKState class (https://github.com/bmwcarit/barefoot/blob/master/src/main/java/com/bmwcarit/barefoot/matcher/MatcherKState.java), you could add something like jsoncandidate.put("length", candidate.transition().route().length());right after line 123 in the body of the if-statement.
2. Since you add the JSON of the transition/route, you could also add json.put("length", length()); in the Route class (https://github.com/bmwcarit/barefoot/blob/master/src/main/java/com/bmwcarit/barefoot/roadmap/Route.java) after line 240.

Route#length() returns the length of the route in meters.

[RobKoch]

Splendid, that works quite well! Thanks for your quick reply.