dear all,
I have a raster GIS map converted to points. Now, I am trying to calculate the nearest neighbor distance for every point to a cluster of points within this map. Since the number of points is more than two millions, I am wondering whether there is a computation efficient way to do this. The following is what the data looks like: point_id,x_coord,y_coord,class 675,-821292,6896866,GL 738,-819294,6895866,GL 803,-819294,6894867,GL 804,-818295,6894867,GL 805,-817296,6894867,GL 806,-816297,6894867,RCK 873,-818296,6893867,GL 874,-817297,6893867,GL 875,-816298,6893868,RCK 876,-815299,6893868,RCK 877,-814300,6893868,RCK 878,-813300,6893868,GL 945,-817297,6892867,GL 946,-816298,6892868,RCK 947,-815299,6892868,RCK 948,-814300,6892868,RCK 949,-813301,6892868,GL 950,-812302,6892869,GL 951,-811303,6892869,GL 1021,-816298,6891868,RCK 1023,-814300,6891868,RCK 1024,-813301,6891869,GL 1025,-812302,6891869,GL 1027,-810304,6891869,GL 1028,-809305,6891870,GL 1029,-808306,6891870,GL 1098,-816299,6890868,RCK 1099,-815300,6890868,RCK 1100,-814301,6890868,GL 1101,-813302,6890869,GL ............................................ I want to calculate, for example, the nearest distances for all GL points to the RCK class. X.W. [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo