Re: [R-sig-Geo] overlay point extraction of pixel radius (3x3 window)

2008-12-10 Thread Roger Bivand
On Wed, 10 Dec 2008, zack holden wrote: Dear list, I would like to use points to extract values from underlying grids, modifying my query to return the mean, standard deviation, or other function of the cells adjacent to the center grid cell. I assume this is possible, but I can find no exa

[R-sig-Geo] overlay point extraction of pixel radius (3x3 window)

2008-12-09 Thread zack holden
Dear list, I would like to use points to extract values from underlying grids, modifying my query to return the mean, standard deviation, or other function of the cells adjacent to the center grid cell. I assume this is possible, but I can find no examples of this in previous posts or in the