log2 R’/G’ = log2 R/G – lowess i(A)
Non-normalized data {(M, A)}n=1..n
M = log2(R/G)
Global normalized data {(M, A)}n=1..n
Mnorm = Mi – ci(A) = log2R/(ki(A)G)
Xinorm = k(A)*Xi
; c(A) = log2(k(A))
c(A) is an intensity dependent function.
or c(A) is the (lowess fit) to the MA-plot.
LOWESS Normalization