adaptive.bin: Adaptive binning

View source: R/adaptive.bin.R

adaptive.binR Documentation

Adaptive binning

Description

This is an internal function. It creates EICs using adaptive binning procedure

Usage

adaptive.bin(x, min.run, min.pres, tol, baseline.correct, weighted=FALSE)

Arguments

x

A matrix with columns of m/z, retention time, intensity.

min.pres

Run filter parameter. The minimum proportion of presence in the time period for a series of signals grouped by m/z to be considered a peak.

min.run

Run filter parameter. The minimum length of elution time for a series of signals grouped by m/z to be considered a peak.

tol

m/z tolerance level for the grouping of data points. This value is expressed as the fraction of the m/z value. This value, multiplied by the m/z value, becomes the cutoff level. The recommended value is the machine's nominal accuracy level. Divide the ppm value by 1e6. For FTMS, 1e-5 is recommended.

baseline.correct

After grouping the observations, the highest intensity in each group is found. If the highest is lower than this value, the entire group will be deleted. The default value is NA, in which case the program uses the 75th percentile of the height of the noise groups.

Details

It uses repeated smoothing and splitting to separate EICs. The details are described in the reference and flowchart.

Value

A list is returned.

height.rec

The records of the height of each EIC.

masses

The vector of m/z values after binning.

labels

The vector of retention time after binning.

intensi

The vector of intensity values after binning.

grps

The EIC labels, i.e. which EIC each observed data point belongs to.

times

All the unique retention time values, ordered.

tol

The m/z tolerance level.

min.count.run

The minimum number of elution time points for a series of signals grouped by m/z to be considered a peak.

weighted

Whether to weight the local density by signal intensities.

Author(s)

Tianwei Yu <tyu8@emory.edu>

References

Bioinformatics. 25(15):1930-36. BMC Bioinformatics. 11:559.


yufree/apLCMS documentation built on May 19, 2024, 1:22 p.m.