addMolecules {Rdisop} | R Documentation

## Add/subtract sum formulae

### Description

Simple arithmetic modifications of sum formulae.

### Usage

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

### Arguments

`formula1` | Sum formula
`formula2` | Sum formula
`elements` | list of allowed chemical elements, defaults to full periodic system of elements

### 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 mass of molecule score dummy value, always 1.0 isotopes a list of isotopes

### Author(s)

Steffen Neumann <sneumann@IPB-Halle.DE>

### Examples

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

[Package Rdisop version 1.0.0 Index]