[R-sig-Geo] matching points to a raster

[Tobias Vetter]

I am not sure if I undersood your problem. Do you like to get 
rastervalues for a point theme? If yes, then
overlay()
might be helpful.
Tobias
> Dear list,
>
> I am trying to incoporate spatial information (for example distance) into a movement model by reading an ascii -b converted raster and matching the raster with points of a movement path (for example fishmove$coord[fishmove$day==1]. Below is a section of my code to explain the problem. This code does not work because the coordinates of the movement path are not the same as those in the raster. Rounding the coordinates does not seem to solve the problem. Maybe the closest point would have to be found, but i am not sure how to approach this.  Is there another perhaps easier way ?
>
> Dist_DF=data.frame(readAsciiGrid("distance.txt"))
> Dist_shoreDF$coord = paste(round(Dist_DF$s1),round(Dist_DF$s2),sep=",")
> names(Dist_DF)[1]="Dist"
> Dist_DF$Dist[Dist_shoreDF$coord==fishmove$coord[fishmove$day==1]]
>
> I would be grateful for any help.
>
> Many thanks,
>
> Juliane
>
>
>
>
>
>
>
> 	[[alternative HTML version deleted]]
>
> _______________________________________________
> R-sig-Geo mailing list
> R-sig-Geo at stat.math.ethz.ch
> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>
>