indexRtime: Convert retention times to retention indices

In rformassspectrometry/MetaboCoreUtils: Core Utils for Metabolomics Data

Convert retention times to retention indices

Description

indexRtime uses a list of known substances to convert retention times (RTs) to retention indices (RIs). By this retention information is normalized for differences in experimental settings, such as gradient delay volume, dead volume or flow rate. By default linear interpolation is performed, other ways of calculation can supplied as function.

Usage

indexRtime(x, y, FUN = rtiLinear, ...)

Arguments

x	numeric vector with retention times
y	data.framedata.frame containing two columns, where the first holds the retention times of the indexing substances and the second the actual index value
FUN	function function defining how the conversion is performed, default is linear interpolation
...	additional parameter used by FUN

Value

numeric vector of same length as x with retention indices. Values floating point decimals. If integer values shall be used conversion has to be performed manually

Author(s)

Michael Witting

Examples

rti <- data.frame(rtime = c(1,2,3),
rindex = c(100,200,300))
rtime <- c(1.5, 2.5)
indexRtime(rtime, rti)

rformassspectrometry/MetaboCoreUtils documentation built on Oct. 2, 2024, 5:13 a.m.