Realizing the main algorithm on R

Hi graphhopper developers,

I’m new to java and map matching. Now I am learning about map matching by myself and feel very interested in it. And I hope to use R to realize the algorithm based on viterbi.

Here are the things I want to do on R (The thoughts exactly come from “Map matching with Hidden Markov Model on sampled road network”). I have a .shp file which stores information of a road network, and .txt files which store the GPS trajectories. First I will store crosspoints for the road network with the kd tree or nearest neighbor data structures. Then for each GPS point,I will sort out crosspoints nearby . Then I apply the Viterbi algorithm on the GPS points and CPs.

I am studying codes here to get some inspiration about how to realize the algorithm on R, like how to store the data, to find out the candidates crosspoints and to apply the Viterbi algorithm. But the codes include not only the algorithm but many other functions about graphhopper. Besides there are many “import” within each file, so I can’t figure out what the codes are talking about until opening the scripts mentioned after these” import”. But when I open these scripts there are still a lot of “import” within, so I feel difficult to find out those I want.

Would you mind telling me which codes here might be helpful for me? Or do you have any recommendations about realizing the algorithm on R? Thank you very much.

Best regards,

So you basically want to rebuild the storage and algorithms in R again?

I would suggest to try this bridge instead:

Yes, I’ll try that.
Thanks for your suggestion!

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