CompDbSource: Compound Annotation Sources for 'CompDb' databases

In michaelwitting/MetaboAnnotation: Utilities for Annotation of Metabolomics Data

Compound Annotation Sources for CompDb databases

Description

CompDbSource objects represent references to CompoundDb::CompDb database-backed annotation resources. Instances are expected to be created with the dedicated construction functions such as MassBankSource or the generic CompDbSource. The annotation data is not stored within the object but will be accessed/loaded within the object's matchSpectra method.

New CompDbSource objects can be created using the functions:

• CompDbSource: create a new CompDbSource object from an existing CompDb database. The (SQLite) database file (including the full path) needs to be provided with parameter dbfile.

• MassBankSource: retrieves a CompDb database for the specified MassBank release from Bioconductor's online AnnotationHub (if it exists) and uses that. Note that AnnotationHub resources are cached locally and thus only downloaded the first time. The function has parameters release which allows to define the desired MassBank release (e.g. release = "2021.03" or release = "2022.06") and ... which allows to pass optional parameters to the AnnotationHub constructor function, such as localHub = TRUE to use only the cached data and avoid updating/retrieving updates from the internet.

Other functions:

• metadata: get metadata (information) on the annotation resource.

Usage

CompDbSource(dbfile = character())

## S4 method for signature 'CompDbSource'
metadata(x, ...)

## S4 method for signature 'CompDbSource'
show(object)

MassBankSource(release = "2021.03", ...)

Arguments

dbfile	character(1) with the database file (including the full path).
x	A CompDbSource object.
...	For CompDbSource: ignored. For MassBankSource: optional parameters passed to the AnnotationHub constructor function.
object	A CompDbSource object.
release	A character(1) defining the version/release of MassBank that should be used.

Author(s)

Johannes Rainer

Examples

## Locate a CompDb SQLite database file. For this example we use the test
## database from the `CompoundDb` package.
fl <- system.file("sql", "CompDb.MassBank.sql", package = "CompoundDb")
ann_src <- CompDbSource(fl)

## The object contains only the reference/link to the annotation resource.
ann_src

## Retrieve a CompDb with MassBank data for a certain MassBank release
mb_src <- MassBankSource("2021.03")
mb_src

michaelwitting/MetaboAnnotation documentation built on Dec. 20, 2024, 5:34 a.m.