\title{Normalization by grid of Spot}
This function normalize R and I values and fit the value of Cy5 for each
grid in the spot that it receives as argument. In this function the
dimension of grid is (meta-row * meta-column).}
grid.norm(mySpot, nr, nc)
\item{mySpot}{Spot object for one microarray.}
\item{nr}{Total of meta-row.}
\item{nc}{Total of meta-column.}
Spot object with the grid normalization done. 
## background correction and save it in c.spot
c.spot <- bg.correct(Simon)
## normalization and save it in n.spot
n.spot <- grid.norm(c.spot, 23, 24)