[R-sig-Geo] how to mask a raster with a coarser resolution selected grid squares ?

[Arnald Marcer]

Dear listers,

Can anybody help me with this ?

How can I mask a 1km UTM grid raster with a list of coordinates
which represent the center of 10km UTM grid squares ? Ultimately
I want the 1km grid raster with only the pixels that fall inside
the 10km UTM grid squares.

Also, how can I build a SpatialPolygonsDataFrame representing 10km
UTM grid squares from a list of coordinates which represent their grid
center.

I will appreciate if you can give me some hints on how to do this.

Arnald Marcer
CREAF