I used limma to read and normalize An Agilent data set , i did not apply the backround correction on it : which is :
y <- backgroundCorrect(x,method="normexp")#
then i found another method which is nec(), neqc () :
y=nec(x, status=NULL, negctrl="negative", regular="regular", offset=16,robust=FALSE, detection.p="Detection")
but i received an error :
Error in normexp.fit.detection.p(x, detection.p) :
Detection p values not found in the data.
please any suggestion