title: Implementing pathfinding in R
body: <p>I am looking for an existing package that provides pathfinding algorithms for 2d data. I have a regular grid with scores and would like to start out with the A* algorithm. </p>
  
  <p>I am surprised that there doesn't seem to be an R package dealing with such a task (obviously, googling for "a* algorithm in R" gives very unspecific results). </p>
  
  <p>Does anyone know of an existing package and if there is none, can point me towards an efficient way of implementing the algorithm in R?</p>
  
  <p>Thanks!</p>