addMolecules: Add/subtract sum formulae

In sneumann/Rdisop: Decomposition of Isotopic Patterns

Add/subtract sum formulae

Description

Simple arithmetic modifications of sum formulae.

Usage

addMolecules(formula1, formula2, elements = NULL, maxisotopes = 10)
subMolecules(formula1, formula2, elements = NULL, maxisotopes = 10)

Arguments

formula1	Sum formula
formula2	Sum formula
elements	list of allowed chemical elements, defaults to full periodic system of elements
maxisotopes	maximum number of isotopes shown in the resulting molecules

Details

addMolecules() adds the second argument to the first. subMolecules() subtracts the second argument from the first.

This can be useful to revert e.g. adduct/fragment formation found in ESI mass spectrometry, or to mimick simple chemical reactions. No chemical checks are performed.

Value

A list with the elements

formula	repeated sum formula
mass	exact monoisotopic mass of molecule
score	dummy value, always 1.0
isotopes	a list of isotopes

Author(s)

Steffen Neumann <[e-mail]>

Examples

# For proton-Adduct of Ethanol:
subMolecules("C2H7O", "H")

sneumann/Rdisop documentation built on Feb. 21, 2023, 2:16 a.m.