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Adjusting an existing path to the map
Posted: Fri Jun 20, 2014 11:29 am
by joaofigueira
I have the following use case that I would like to know if it is possible to implement (and how):
- Given an existing vehicle path, determine the incurred toll costs.
Toll costs are calculated using the route service, but this service does not seem to cope very well when fed with real GPS-generated vehicle locations (lat / long pairs). This is understandable because the sampled vehicle GPS data is not exact and some of these points lie outside of the road or, on some occasions, might even lie on adjacent roads. After feeding this type of data to the route service I got multiple crossings of the same toll, or multiple crossings in opposite directions.
It seems clear that my data needs to, somehow, be "adjusted" to the map so that it can then be fed to the route service. Can this be done with the map match service?
TIA
Re: Adjusting an existing path to the map
Posted: Mon Jun 23, 2014 7:00 am
by Joost
This can be done by xMapmatch. You fan feed the GPS coordinates to xMapmatch and receive correct coordinates back. Apart from the corrected coordinates you also receive the segment id. You can use this to feed the xRoute to have it calculate the exact routing with the toll costs details.
You can have a look at my test client
http://xserver.ptvgroup.com/forum/viewt ... p?f=8&t=12 . It comes with c# source code.
Note: since GPS signals are very different from each other (different accuracy, different poll rate), using the proper profile becomes really important to get out a proper result. If you do not get proper result i would recommend having you data analysed to come up with a better profile to suit your needs.
Re: Adjusting an existing path to the map
Posted: Wed Jun 25, 2014 2:04 pm
by joaofigueira
Hi,
Thank you for your sample. It really is helping me figure out what information I was missing. You mention a "profile" for the data input (set on the CallerContext). Where can I read more about this profile?
Regards,
JP
Re: Adjusting an existing path to the map
Posted: Wed Jun 25, 2014 2:40 pm
by Bernd Welter
Hello Joao,
within your xMapmatch server's configuration folder there are several files named xmapmatch-[profilename].properties:
- xmapmatch-default.properties
- xmapmatch-dense-signal.properties
- xmapmatch-local-matching.properties
- xmapmatch-sparse-signal.properties
These files contain a lot of additional algorithm parameters that have important impact on the quality of the results.
Now by using a specific CallerContext and it's profile value you can request which file to be used (default is the standard)
Code: Select all
<ns2:CallerContext_5>
<ns6:wrappedProperties>
<ns6:CallerContextProperty value="sparse-signal" key="Profile"/>
</ns6:wrappedProperties>
</ns2:CallerContext_5>
Now please have a look the files and the descriptions of the parameters. If necessary you can also create a new profile
xmapmatch-joaorules.properties and adapt the values in the way you want...
Does this answer the question?
Regards Bernd
Re: Adjusting an existing path to the map
Posted: Wed Jun 25, 2014 3:01 pm
by joaofigueira
Hi Bernd,
I believe this does answer my question. I am changing my code in order to reflect Joost's code sample because it did seem to provide a quite accurate match to my data. I am also looking at the contents of these files in order to check if I need to customize any of the parameters.
Thank you very much!
JP
Re: Adjusting an existing path to the map
Posted: Wed Jun 25, 2014 4:48 pm
by joaofigueira
Hi Bernd,
Should I see these files somewhere in my project directory, or are these downloadable from the web?
Thanks!
JP
Re: Adjusting an existing path to the map
Posted: Thu Jun 26, 2014 7:28 am
by Bernd Welter
Hello Joao,
depends:
- Local installation
in case of a local installation you should find the files in the CONF folder, see attached screenshot of my laptop.
- xServer internet aka xSaaS
If you use xServer internet aka xSaaS you need to know the names of the available files and you can't add further files because the configuration is fix.
Regards Bernd
Re: Adjusting an existing path to the map
Posted: Thu Jun 26, 2014 11:50 am
by Bernd Welter
About xSaaS:
the available profiles are listed in the
http://xserver.ptvgroup.com/en-uk/cookb ... formation/
Just check the section
Available xServers and Addons
https://svc-eu-n-test.cloud.ptvgroup.co ... rInfo.ashx
Bernd
Re: Adjusting an existing path to the map
Posted: Wed Jul 09, 2014 1:29 pm
by Joost
Extra note about the profiles:
From version 1.18.1 xml profiles are being used instead of properties files. You now can find them in the <xMapmatch directory>/conf/profiles directory. The reference documentation for profiles:
http://xserver.ptvgroup.com/fileadmin/f ... e%7C_____0
If you need to convert old profiles, please use the converter which is included in the xMapmatch. You can find the converter in the <xMapmatch directory>/tools/profileconverter directory. There is a html file with documentation how to use the converter included in this directory.