Filter ions/peaks based on retention time hierarchical clustering, paired mass distances(PMD) and PMD frequency analysis.

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,
  corcutoff = NULL
)

Arguments

list

a peaks list with mass to charge, retention time and intensity data

rtcutoff

cutoff of the distances in retention time hierarchical clustering analysis, default 10

ng

cutoff of global PMD's retention time group numbers, If ng = NULL, 20 percent of RT cluster will be used as ng, default NULL.

digits

mass or mass to charge ratio accuracy for pmd, default 2

accuracy

measured mass or mass to charge ratio in digits, default 4

corcutoff

cutoff of the correlation coefficient, 0.6 is suggested, default NULL

Value

list with tentative isotope, multi-chargers, adducts, and neutral loss peaks' index, retention time clusters.

See also

getstd,getsda,plotpaired

Examples

data(spmeinvivo)
pmd <- getpaired(spmeinvivo)
#> 75 retention time clusters found.
#> Using ng = 15
#> 5 unique PMDs retained.
#> The unique within RT clusters high frequency PMD(s) is(are)  28.03 21.98 44.03 17.03 18.01.
#> 409 isotope peaks found.
#> 109 multiple charged isotope peaks found.
#> 251 multiple charged peaks found.
#> 346 paired peaks found.