listAttributes: lists the attributes available in the selected dataset
In biomaRt: Interface to BioMart databases (i.e. Ensembl)

Description Usage Arguments Author(s) Examples

Attributes are the outputs of a biomaRt query, they are the information we want to retrieve. For example if we want to retrieve all EntrezGene identifiers of genes located on chromosome X, entrezgene_id will be the attribute we use in the query. The listAttributes function lists the available attributes in the selected dataset.

1 2	listAttributes(mart, page,what = c("name","description","page")) searchAttributes(mart, pattern)

`mart`	object of class Mart created using the useMart function
`page`	Show only the attributes that belong to the specified attribute page.
`what`	vector of types of information about the attributes that need to be displayed. Can have values like name, description, fullDescription, page
`pattern`	Character vector defining the regular expression (`regex)` to be used for the search. If left blank the default is to use ".*" which will match everything.

Steffen Durinck, Mike Smith

if(interactive()){

    ## list the available Ensembl marts and use Ensembl Genes
    listEnsembl()
    ensembl <- useEnsembl(biomart = "ensembl", dataset = 'hsapiens_gene_ensembl')

    ## list the available datasets in this Mart
    listAttributes(mart = ensembl)

    ## the list of attributes is very long and gets truncated by R
    ## we can search for a term of interest to filter this e.g. 'start'
    searchAttributes(mart = ensembl, pattern = "start")
    
    ## filter the attributes to give only entries containing 'entrez' or 'hgnc'
    searchAttributes(mart = ensembl, 'entrez|hgnc') 
}