I've used the cost path utility to find the least cost path on sea to a number of ports from one source. I want to assign the pathcost field to each port. I've used the extract values to points tool to assign to each port the pathcost field. This works fine except for one port where I get that the raster value is -9999 and the pathcost is 0 even though I can see from the cost path raster's attribute table that it has a sensible (ie. positive) value in the pathcost field.
I suspect the problem is that this port is en route to another port upriver and therefore it has the value 2 assigned to it on the whole of its least cost path route.
I'm new to ArcGIS so any help is much appreciated!
Reka
