[R-sig-Geo] calculate raster values based on vector regions

[Alexander.Herr at csiro.au]

Hi List,

How would I go about assigning values to a raster based on polygon regions in R. Examples would be most appreciated.

I have (vector) regions assigned to a specific value. The raster has NAs and some pixels where these values are likely to occur on ground. I need to assign these values to the raster and can do this in ArcInfo through vectors and rasterizing but only to a limited raster size. And R is much more preferable anyway...

Any help appreciated.
Cheers
Herry