[R-sig-Geo] Apply a look-up table using Raster package

[Ned Horning]

Hi - Is it possible to modify a Raster layer using a look-up table? I 
have a data.frame object with data to map pixel values in a Raster layer 
from one value to another but I'm not sure how to apply it. I tried to 
be creative with setValues but didn't get too far.

All the best,

Ned