On Thu, May 19, 2011 at 4:17 PM, Edzer Pebesma <[email protected]> wrote:
> Does that get you any further? Or are there more clever solutions? >> So far I have got the result in this plot from an iterative procedure >> using the FROMJCT and TOJCT (from and to junction) IDs of the data.frame: If the FROMJCT and TOJCT numbers define nodes of a graph, and the presence of a row with FROMJCT=a and TOJCT=b defines an edge from a to b of the graph, then you could use something like R's igraph package to build a graph object. Once you've done that it should be easy to use the graph algorithms in that package to wander down the river system at your leisure... It might get complicated if you are modelling on the Orinoco where it bifurcates, or a river delta :) Will have a play now at the end of the working day while waiting for the Indian Premier League Cricket to start up again... Barry _______________________________________________ R-sig-Geo mailing list [email protected] https://stat.ethz.ch/mailman/listinfo/r-sig-geo
