[R] exporting rast from R to GRASS

[Thybério Luna Freire]

Hi, everybody!
i created a imagem by kriging using geoR package. I imported  points
from GRASS("zn", after converted to geodata "zn_geo"), the border
"zn_border" and a raster mask. Then i interpolated the points by
kriging and created a raster image. Now, i need export this image back
to GRASS to use it in the module r.mapcalc. I can't do it. I tried use
writeRAST6, but it returns a message:  "tentativa de obter um slot
"data" de um objeto cuja classe ("kriging") não é um objeto S4" or
"attempt to obtain a slot from an object whose class ("kriging") is
not a S4 object". what does this mean?
Help me, please!

Thybério Luna - Brazil