I have to point shapefiles and would like to extract values from one point shapefile to another one based on some measure of proximity, i.e. for any given point in dataset x, extract the mean value for all points in dataset y within a 10km radius of the given point in dataset x. Or, for any given point in x, extract the value of the closest point in y and add to x.
I'm familiar with extract function in r to extract raster values to point. Not sure if sample data would help in this one, but would like to do this in r, or failing that, ArcGIS Desktop.