graphhopper / map-matching

The map matching functionality is now located in the main repository https://github.com/graphhopper/graphhopper#map-matching
https://www.graphhopper.com/open-source/
Apache License 2.0
785 stars 273 forks source link

Enable GPS-precise map matching #51

Closed MK-42 closed 6 years ago

MK-42 commented 8 years ago

Added Fetching of wayGeometry on the virtual edges at start and end of the gpxTrack. Closes #50

I don't know if you have any special code-formatting constraints as line length. Could change that if needed.

What do you think about that approach

karussell commented 8 years ago

Thanks & Looks good.

Now only the web module needs to implement and use this too. Also I would like to hide this somehow from public usage in MatchResult, hmmh, not sure how.

karussell commented 8 years ago

Ah, maybe we add a 'getWayGeometry' method to EdgeMatch and do a fallback if non-existing?

PointList getWayGeometry() {
   if(geometry != null)
      return geometry;
   else
      return edgeState.fetchWaygeometry(0);
}

Then we can change the web API from:

PointList pointList = edgeMatch.getEdgeState().fetchWayGeometry(emIndex == 0 ? 3 : 2);

to

PointList pointList = edgeMatch.getWayGeometry();
MK-42 commented 8 years ago

done i think. Much smoother to use now. good idea!

MK-42 commented 8 years ago

but i forgot the change in the web service. will push that next btw: doesn't the Console-Version need that change too to be gps precise?

MK-42 commented 8 years ago

did some more changes to make using easier. What do you think @karussell ?

MK-42 commented 8 years ago

sorry, had wrong indentation settings and messed it up a little bit.

I think I've adressed your points. The setWayGeometry part is not that nice in the phase 4, because we need it two times and i didn't want to duplicate the conditions... but extracting that is also not that nice because of the index-params.

What do you think?

karussell commented 8 years ago

I think I've adressed your points.

Thanks!

Looks now indeed better. Will investigate (after next week) why there is the time difference and how to improve this "The setWayGeometry part is not that nice in the phase 4"

sorry, had wrong indentation settings and messed it up a little bit.

No problem

karussell commented 8 years ago

These differences in time should come from the edge vs. virtual edge and normally should be fixed with these changes here. A bit strange.

Now after a bit thinking and struggling I think it is more valuable to merge #49 before or merge both at the same time. I'll let you know once this is done (hopefully in the next 2 weeks) - thanks a lot for this change!

MK-42 commented 8 years ago

Anything i can do to get that merged an in the next Release (i think there is an upcoming. Right?) Then I could also Test the hmm stuff.

karussell commented 8 years ago

Anything i can do to get that merged an in the next Release (i think there is an upcoming. Right?)

Sorry, the release is already kind of out. But will make a merge afterwards and hopefully the next release won't last long. Currently we plan to release more often and delay the features instead of delaying the release with planned features.

I also hoped that I could this working within the release but it would have taken too long. The hmm stuff needs some more tuning and will include it but make it optional to allow a fallback to the old algorithm ... this all makes it a bit more work than currently done.

karussell commented 8 years ago

I stumbled over a new problem where also in-between edges needs this GPS precision, not only start and end. E.g. a tracked truck delivers a dead end road and needs to go forth&back.

karussell commented 8 years ago

The "hmm" work is now better integrated and I would like to push this issue forward now. @MK-42 Would you have some time to invest in this issue soonish? Otherwise I'll have to move this to another version/release.

aminefalek commented 7 years ago

Hello guys, I would like to use this precise map matching feature. I thus downloaded different versions that correspond to the changes you are talking about here. To be precise, I downloaded and tested the following versions:

https://github.com/graphhopper/map-matching/tree/9606f2fc28f7b0d801e97a5e36f830014a147d85 https://github.com/graphhopper/map-matching/tree/7005e9c901788e7aed862e78cb6499946daddf58 https://github.com/graphhopper/map-matching/tree/2cef7f298c9f44f1a294a91eb3d5b7dc283fe009

All three versions returned the same result (which isn't precise), that can be seen here: screenshot

The gpx file I am using as input is this one: 120+00085_13643.zip

I am probably doing something wrong, can you please explain what I should do to get it working ?

michaz commented 6 years ago

Fixed this in e380cef (by doing less work: concatenating the Paths returned from map-matching instead of reconstructing a new one (where the begin/end-splits are missing))

karussell commented 6 years ago

Really cool - thanks a bunch!