taNorm: Total Area Normalisation

In kylebario/unorm: Urine Normalisation

Description

Total area normalisation (TA) scales spectra so that they all have a total integral of one

Usage

taNorm(X, noi)

Arguments

X	A numerical matrix with rows being the spectra and columns being the chemical shift variables
noi	Takes an array that is row matched to the X matrix you are normalising with the values equaling the maximum noise estimation for each spectra respectively.

Details

How It Works:

1. The integral of each experimental spectra in X is calculated

2. Each intensity of a spectrum is divided by it's integral which reduces it's total area to one

Background Information:

• TA was once considered the gold standard in NMR spectra normalisation.

• TA is also referred to as constant sum or integral normalisation

• TA is useful for spectra that have similar peaks.

Advantages:

• TA is a straightforward normalisation method with limited computational requirements making it quick and uncomplicated.

• Combining both TA and another normalisation method could also provide more robust results.

Limitations:

• Large variation in the peaks present in a spectra severly impact TA's performance.

• For instance, some spectra have large peaks created by drug metabolites, etc., which increase the total area of the spectrum.

• This large total area will then dramatically down scale spectra and give misleading results.

Value

A list of

1. The normalised X matrix in the first list element, and

2. A numerical array of the corresponding dilution factors.

• Following the example below will extract the results quickly and easily.

Author(s)

[e-mail]

See Also

https://doi.org/10.1021/ac051632c

Other Attribute-Based: creNorm(), qNorm(), roiNorm(), vecNorm()

Examples

data(X, noi)
taNorm(X, noi)
cat(dilf_ta)

kylebario/unorm documentation built on Dec. 21, 2021, 8:45 a.m.