Selecting present prob-id after performing pa.calls function from panp package on eSet

Question

[Shamim Sarhadi]

Hi , suppose I have an eSet with 30 control and 70 cancer sample, I performed pa.calls function from panp package an my eSet, now I have a matrix included P,M and A calls , please tell me how can I select P calls prob-ids from original eset ,Please let me know if you have any suggestion, I run these codes

table(pData(eset)[,Disease])

70:cancer        30:control

PA<-pa.calls(eset)
Processing 100 chips####

mypcalls<-PA$Pcalls
keep <- rowSums(mypcalls=="P") ??????

how should I complete above codes?