Filter ions/peaks based on retention time hierarchical clustering, paired mass distances(PMD) and PMD frequency analysis.
getpaired( list, rtcutoff = 10, ng = NULL, digits = 2, accuracy = 4, mdrange = NULL )
a list with mzrt profile
cutoff of the distances in retention time hierarchical clustering analysis, default 10
cutoff of global PMD's retention time group numbers, If ng = NULL, 20 percent of RT cluster will be used as ng, default NULL.
mass or mass to charge ratio accuracy for pmd, default 2
measured mass or mass to charge ratio in digits, default 4
mass defect range to ignore. Default NULL and c(0.25,0.9) to retain the possible reaction related paired mass
list with tentative isotope, multi-chargers, adducts, and neutral loss peaks' index, retention time clusters.
data(spmeinvivo) pmd <- getpaired(spmeinvivo) #> 75 retention time cluster found. #> 369 paired masses found #> 5 unique within RT clusters high frequency PMD(s) used for further investigation. #> The unique within RT clusters high frequency PMD(s) is(are) 28.03 21.98 44.03 17.03 18.01. #> 719 isotopologue(s) related paired mass found. #> 492 multi-charger(s) related paired mass found.