FAMEoutliers: FAME outlier detection

Description

A function to detect retention time marker (FAME) outliers.

Usage

FAMEoutliers(samples, RImatrix, pdffile = NA, startDay = NA, endDay = NA, threshold = 3, group.threshold = 0.05)

Arguments

samples

A tsSample object created by ImportSamples function.

RImatrix

A retention time matrix of the found retention time markers.

pdffile

A character string naming a PDF file where the FAMEs report will be saved.

startDay

A numeric vector with the starting days of your day groups.

endDay

A numeric vector with the ending days of your day groups.

threshold

A standard deviations cutoff to detect outliers.

group.threshold

A numeric cutoff to detect day groups based on hierarchical clustering. Must be between 0..1.

Value

A logical matrix of the same size of RImatrix. A TRUE value indicates that the retention time marker in that particular sample is an outlier.

Details

If no pdffile argument is given, the report will be saved on a file called "TargetSearch-YYYY-MM-DD.FAME-report.pdf", where YYYY-MM-DD is a date.

If both startDay and endDay are not given, the function will try to detect day groups using a hierarchical clustering approach by cutting the tree using group.threshold as cutoff height.

Retention time markers that deviate more than threshold standard deviations from the mean of their day group will be identified as outliers.

Examples

Run this code

require(TargetSearchData)
data(TargetSearchData)

# find the retention marker outliers of the example data and save it in "outlier.pdf"
outliers <- FAMEoutliers(sampleDescription, RImatrix, pdffile = "outlier.pdf")

# find the outliers (although they are reported in the output PDF file)
apply(outliers, 1, which)